Patent Publication Number: US-2022235413-A1

Title: Recombinant polymerases for incorporation of protein shield nucleotide analogs

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. Ser. No. 16/812,657, filed Mar. 9, 2020, which is a continuation of U.S. Ser. No. 15/842,467, filed Dec. 14, 2017, now U.S. Pat. No. 10,626,456, which is a continuation of U.S. Ser. No. 15/188,672, filed Jun. 21, 2016, now U.S. Pat. No. 9,873,911, which is a continuation of U.S. Ser. No. 14/042,318, filed Sep. 30, 2013, now U.S. Pat. No. 9,399,766, which claims priority to and benefit of the following prior provisional patent applications: U.S. Ser. No. 61/781,845, filed Mar. 14, 2013, entitled “RECOMBINANT POLYMERASES FOR INCORPORATION OF PROTEIN SHIELD NUCLEOTIDE ANALOGS” by Satwik Kamtekar and Erik Miller, U.S. Ser. No. 61/764,971, filed Feb. 14, 2013, entitled “RECOMBINANT POLYMERASES FOR INCORPORATION OF PROTEIN SHIELD NUCLEOTIDE ANALOGS” by Satwik Kamtekar and Erik Miller, and U.S. Ser. No. 61/708,469, filed Oct. 1, 2012, entitled “RECOMBINANT POLYMERASES WITH INCREASED READLENGTH AND STABILITY FOR SINGLE-MOLECULE SEQUENCING ” by Satwik Kamtekar and Erik Miller. Each of these applications is incorporated herein by reference in its entirety for all purposes. 
    
    
     INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED BY U.S.P.T.O. eFS-WEB 
     The instant application contains a Sequence Listing which is being submitted in computer readable form via the United States Patent and Trademark Office eFS-WEB system and which is hereby incorporated by reference in its entirety for all purposes. The txt file submitted herewith contains a 566 KB file (01016906_2022-04-12_SequenceListing.txt). 
     FIELD OF THE INVENTION 
     The invention relates to modified DNA polymerases for single molecule sequencing and nucleic acid amplification. The polymerases include recombinant polymerases that exhibit enhanced utility with large nucleotide analogs. The invention also relates to methods for amplifying nucleic acids and to methods for determining the sequence of nucleic acid molecules using such polymerases. 
     BACKGROUND OF THE INVENTION 
     DNA polymerases replicate the genomes of living organisms. In addition to this central role in biology, DNA polymerases are also ubiquitous tools of biotechnology. They are widely used, e.g., for reverse transcription, amplification, labeling, and sequencing, all central technologies for a variety of applications such as nucleic acid sequencing, nucleic acid amplification, cloning, protein engineering, diagnostics, molecular medicine, and many other technologies. 
     Because of the importance of DNA polymerases, they have been extensively studied. This study has focused, e.g., on phylogenetic relationships among polymerases, structure of polymerases, structure-function features of polymerases, and the role of polymerases in DNA replication and other basic biological processes, as well as ways of using DNA polymerases in biotechnology. For a review of polymerases, see, e.g., Hübscher et al. (2002) “Eukaryotic DNA Polymerases” Annual Review of Biochemistry Vol. 71: 133-163, Alba (2001) “Protein Family Review: Replicative DNA Polymerases” Genome Biology 2(1): reviews 3002.1-3002.4, Steitz (1999) “DNA polymerases: structural diversity and common mechanisms” J Biol Chem 274:17395-17398, and Burgers et al. (2001) “Eukaryotic DNA polymerases: proposal for a revised nomenclature” J Biol Chem. 276(47): 43487-90. Crystal structures have been solved for many polymerases, which often share a similar architecture. The basic mechanisms of action for many polymerases have been determined. 
     A fundamental application of DNA technology involves various labeling strategies for labeling a DNA that is produced by a DNA polymerase. This is useful in DNA sequencing, microarray technology, SNP detection, cloning, PCR analysis, and many other applications. Labeling is often performed in various post-synthesis hybridization or chemical labeling schemes, but DNA polymerases have also been used to directly incorporate various labeled nucleotides in a variety of applications, e.g., via nick translation, reverse transcription, random priming, amplification, the polymerase chain reaction, etc. See, e.g., Giller et al. (2003) “Incorporation of reporter molecule-labeled nucleotides by DNA polymerases. I. Chemical synthesis of various reporter group-labeled 2′-deoxyribonucleoside-5′-triphosphates” Nucleic Acids Res. 31(10):2630-2635, Augustin et al. (2001) “Progress towards single-molecule sequencing: enzymatic synthesis of nucleotide-specifically labeled DNA” J. Biotechnol. 86:289-301, Tonon et al. (2000) “Spectral karyotyping combined with locus-specific FISH simultaneously defines genes and chromosomes involved in chromosomal translocations” Genes Chromosom. Cancer 27:418-423, Zhu and Waggoner (1997) “Molecular mechanism controlling the incorporation of fluorescent nucleotides into DNA by PCR” Cytometry, 28:206-211, Yu et al. (1994) “Cyanine dye dUTP analogs for enzymatic labeling of DNA probes” Nucleic Acids Res. 22:3226-3232, Zhu et al. (1994) “Directly labeled DNA probes using fluorescent nucleotides with different length linkers” Nucleic Acids Res. 22:3418-3422, and Reid et al. (1992) “Simultaneous visualization of seven different DNA probes by in situ hybridization using combinatorial fluorescence and digital imaging microscopy” Proc. Natl Acad. Sci. USA, 89:1388-1392. 
     DNA polymerase mutants have been identified that have a variety of useful properties, including altered nucleotide analog incorporation abilities relative to wild-type counterpart enzymes. For example, Vent A488L  DNA polymerase can incorporate certain non-standard nucleotides with a higher efficiency than native Vent DNA polymerase. See Gardner et al. (2004) “Comparative Kinetics of Nucleotide Analog Incorporation by Vent DNA Polymerase” J. Biol. Chem. 279(12):11834-11842 and Gardner and Jack “Determinants of nucleotide sugar recognition in an archaeon DNA polymerase” Nucleic Acids Research 27(12):2545-2553. The altered residue in this mutant, A488, is predicted to be facing away from the nucleotide binding site of the enzyme. The pattern of relaxed specificity at this position roughly correlates with the size of the substituted amino acid side chain and affects incorporation by the enzyme of a variety of modified nucleotide sugars. 
     Additional modified polymerases, e.g., modified polymerases that display improved properties useful for single molecule sequencing (SMS) and other polymerase applications (e.g., DNA amplification, sequencing, labeling, detection, cloning, etc.), are desirable. The present invention provides new recombinant DNA polymerases with desirable properties, including enhanced sequencing with large nucleotide analogs, increased readlength, and increased thermostability. Other exemplary properties include exonuclease deficiency, increased cosolvent resistance, increased sensitivity to modified bases, altered cofactor selectivity, increased yield, increased resistance to photodamage, increased accuracy, increased speed, and the like. Also included are methods of making and using such polymerases, as well as many other features that will become apparent upon a complete review of the following. 
     SUMMARY OF THE INVENTION 
     Modified DNA polymerases can find use in such applications as, e.g., single-molecule sequencing (SMS), genotyping analyses such as SNP genotyping using single-base extension methods, sample preparation, and real-time monitoring of amplification, e.g., RT-PCR. Among other aspects, the invention provides compositions comprising recombinant polymerases that comprise mutations which confer properties which can be particularly desirable for these and other applications. These properties can, e.g., improve performance with large nucleotide analogs, increase enzyme (and therefore assay) robustness, increase readlength, facilitate readout accuracy, or otherwise improve polymerase performance Also provided by the invention are methods of generating such modified polymerases and methods in which such polymerases can be used to, e.g., sequence a DNA template and/or make a DNA. 
     In one aspect, the invention provides compositions and sequencing systems that include one or more large nucleotide analogs (for example, an analog that includes a protein or other moiety that shields the polymerase from damage by one or more fluorescent dyes in the analog) and a polymerase modified to optimize usage of the large analog, e.g., in single-molecule sequencing or another application. Accordingly, one general class of embodiments provides a composition that comprises a recombinant DNA polymerase (e.g., a Φ29-type DNA polymerase) and optionally a nucleotide analog. The recombinant polymerase comprises one or more mutation that enhances performance with the analog, for example, one or more mutation that decreases interpulse distance, increases pulse width, reduces pausing, increases stability (e.g., free polymerase, binary complex, and/or or ternary complex stability), and/or increases accuracy, e.g., as compared to a corresponding wild-type or other parental polymerase (e.g., a polymerase from which the modified recombinant polymerase of the invention was derived, e.g., by mutation). 
     Accordingly, in one class of embodiments, the recombinant polymerase comprises one or more mutation selected from the group consisting of an amino acid substitution at position Q99, an amino acid substitution at position A134, an amino acid substitution at position K138, an amino acid substitution at position V141, an amino acid substitution at position L142, an amino acid substitution at position A256, an amino acid substitution at position R306, an amino acid substitution at position R308, an amino acid substitution at position K311, an amino acid substitution at position T441, an amino acid substitution at position E466, an amino acid substitution at position D476, an amino acid substitution at position S487, an amino acid substitution at position E508, an amino acid substitution at position L513, an amino acid substitution at position D523, an amino acid substitution at position I524, an amino acid substitution at position K536, an amino acid substitution at position P558, an amino acid substitution at position D570, and an amino acid substitution at position T571, wherein identification of positions is relative to SEQ ID NO:1. For example, the polymerase optionally comprises one or more mutation selected from the group consisting of an A256S substitution, an S487A substitution, a V141K substitution, an L142K substitution, a D476H substitution, an E508R substitution, a D523R substitution, a Q99P substitution, a Q99Y substitution, an R306Q substitution, an R308L substitution, a K311E substitution, a T441I substitution, a D570S substitution, a D570T substitution, a D570E substitution, a D570M substitution, an A134S substitution, an I524S substitution, an I524T substitution, an E466K substitution, an L513K substitution, a T571V substitution, a T571A substitution, a P558A substitution, a P558F substitution, a K138Q substitution, a K138C substitution, a K138A substitution, a K536Q substitution, a K536T, and a K536E substitution, wherein identification of positions is relative to wild-type Φ29 polymerase (SEQ ID NO:1). 
     The polymerase can also include mutations at additional positions. For example, the polymerase can include one or more mutation selected from the group consisting of an amino acid substitution at position 224, an amino acid substitution at position 239, an amino acid substitution at position 253, an amino acid substitution at position 375, an amino acid substitution at position 437, an amino acid substitution at position 484, an amino acid substitution at position 510, an amino acid substitution at position 512, and an amino acid substitution at position 515, wherein identification of positions is relative to SEQ ID NO:1. For example, the polymerase optionally includes one or more mutation selected from the group consisting of a Y224K substitution, an E239G substitution, an L253A substitution, an E375Y substitution, an A437G substitution, an A437N substitution, an A484E substitution, a D510K substitution, a K512Y substitution, and an E515Q substitution, wherein identification of positions is relative to SEQ ID NO:1. 
     Optionally, the polymerase comprises mutations at two, three, four, five, six, seven, eight, nine, ten, or even eleven or more of these positions. For example, the polymerase can include a mutation at position E375, a mutation at position K512, and a mutation at one or more additional positions, e.g., as described herein. Similarly, for example, the polymerase can comprise mutations at positions 375, 512, and 253, positions 375, 512, and 484 (e.g., E375Y, A484E, and K512Y substitutions), positions 253 and 484, positions 375, 512, 253, and 484, positions 375, 512, 253, 484, and 510, positions 253 and 437, positions 239, 253, 375, 437, 484, 510, 512, and 515, or positions 224, 239, 253, 375, 437, 484, 510, 512, and 515, and a mutation at one or more additional positions, e.g., as described herein, where identification of positions is relative to wild-type Φ29 polymerase (SEQ ID NO:1). A number of exemplary substitutions at these (and other) positions are described herein. 
     As a few examples, the recombinant polymerase can comprise a combination of mutations selected from the group consisting of aa) V141K, L142K, Y224K, E239G, V250I, L253A, A256S, R306Q, R308L, K311E, E375Y, A437G, T441I, A484E, S487A, E508R, D510K, K512Y, and E515Q; ab) Y224K, E239G, V250I, L253A, A256S, E375Y, A437G, A484E, S487A, D510K, K512Y, and E515Q; ac) V141K, L142K, Y224K, E239G, V250I, L253A, A256S, E375Y, A437G, T441I, A484E, S487A, E508R, D510K, K512Y, E515Q, and D570E; ad) A134S, Y224K, E239G, V250I, L253A, A256S, E375Y, A437G, A484E, S487A, D510K, K512Y, and E515Q; ae) Y224K, E239G, V250I, L253A, E375Y, A437G, A484E, E508R, D510K, K512Y, E515Q, and D570M; at) A134S, Y224K, E239G, V250I, L253A, E375Y, A437G, A484E, S487A, E508R, D510K, K512Y, E515Q, I524S, F526L, and D570E; ag) L142K, Y224K, E239G, V250I, L253A, E375Y, A437G, D476H, A484E, E508R, D510K, K512Y, L513K, E515Q, and D570E; ah) L142K, Y224K, E239G, V250I, L253A, R306Q, R308L, E375Y, A437G, D476H, A484E, E508R, D510K, K512Y, L513K, E515Q, and D570E; ai) L142K, Y224K, E239G, V250I, L253A, R306Q, R308L, E375Y, A437G, E466K, D476H, A484E, E508R, D510K, K512Y, L513K, E515Q, and D570E; aj) L142K, Y224K, E239G, V250I, L253A, R306Q, R308L, E375Y, A437G, E466K, D476H, A484E, E508R, D510K, K512Y, E515Q, and D570E; ak) L142K, Y224K, E239G, V250I, L253A, E375Y, A437G, E466K, D476H, A484E, E508R, D510K, K512Y, E515Q, and D570E; al) L142K, Y224K, E239G, V250I, L253A, E375Y, M429A, A437G, A484E, E508R, D510K, K512Y, E515Q, and D570E; am) A134S, L142K, Y224K, E239G, V250I, L253A, E375Y, A437G, A484E, S487A, E508R, D510K, K512Y, E515Q, I524S, F526L, and D570E; an) Y224K, E239G, V250I, L253A, E375Y, A437G, A484E, S487A, E508R, D510K, K512Y, E515Q, I524S, F526L, and D570M; ao) C106S, E239G, V250I, L253A, E375Y, A437G, A484E, E508R, D510K, K512Y, and E515Q; ap) L142K, Y224K, D235E, E239G, V250A, L253H, E375Y, A437G, A484E, E508R, D510K, K512Y, E515Q, and D570E; aq) Y224K, E239G, V250I, L253A, E375Y, A437G, A484E, E508R, D510K, K512Y, and E515Q; ar) V141K, L142K, Y224K, E239G, V250I, L253A, E375Y, A437G, A484E, E508R, D510K, K512Y, and E515Q; as) K135Q, L142K, Y224K, E239G, V250I, L253A, R306Q, R308L, E375Y, A437G, E466K, D476H, A484E, E508R, D510R, K512Y, E515Q, D570S, and T571V; at) K131E, K135Q, L142K, Y224K, E239G, V250I, L253A, E375Y, A437G, A484E, E508R, D510R, K512Y, E515Q, D523R, P558A, D570S, and T571V; au) A49E, C106S, K114R, K131E, K135Q, L142K, Y224K, E239G, V250I, L253A, Y369E, E375Y, A437G, D476H, A484E, E508R, D510K, K512Y, E515Q, D523R, D570S, and T571V; av) K135Q, K138Q, L142K, Y224K, E239G, V250I, L253A, R306Q, R308L, E375Y, A437G, E466K, D476H, A484E, E508R, D510K, K512Y, E515Q, I524T, P558A, D570S, and T571V; aw) K135Q, K138Q, L142K, Y224K, E239G, V250I, L253A, R306Q, R308L, E375Y, A437G, E466K, V475I, D476H, A484E, E508R, D510K, K512Y, E515Q, I524T, P558A, D570S, and T571V; ax) K135Q, K138Q, L142K, Y224K, E239G, V250I, L253A, R306Q, R308L, T368S, E375Y, A437G, E466K, D476H, A484E, E508R, D510K, K512Y, E515Q, I524T, P558A, D570S, and T571V; ay) K135Q, K138Q, L142K, Y224K, E239G, V250I, L253A, R306Q, R308L, T368S, E375Y, A437G, E466K, V475I, D476H, A484E, E508R, D510K, K512Y, E515Q, P558A, D570S, and T571V; az) L44A, K135Q, K138Q, L142K, Y224K, E239G, V250I, L253A, R306Q, R308L, E375Y, A437G, E466K, D476H, A484E, S487A, E508R, D510K, K512Y, E515Q, P558A, D570S, and T571V; ba) K135Q, L142K, Y224K, E239G, V250I, L253A, R306Q, R308L, T368S, E375Y, A437G, E466K, D476H, A484E, E508R, D510R, K512Y, E515Q, P558A, D570S, and T571V; bb) A49E, C106S, K114R, K135Q, L142K, Y224K, E239G, V250I, L253A, R306Q, R308L, E375Y, A437G, E466K, D476H, A484E, E508R, D510R, K512Y, E515Q, K536Q, K539Q, D570S, and T571V; bc) L44A, K135Q, K138Q, L142K, Y224K, E239G, V250I, L253A, R306Q, R308L, T368S, E375Y, A437G, E466K, D476H, A484E, E508R, D510K, K512Y, E515Q, P558A, D570S, and T571V; bd) L142K, Y224K, E239G, V250I, L253A, R306Q, R308L, E375Y, A437G, E466K, D476H, A484E, E508R, D510K, K512Y, E515Q, P558A, D570T, and T571A; be) K138C, L142K, Y224K, E239G, V250I, L253A, R306Q, R308L, E375Y, A437G, E466K, D476H, A484E, E508R, D510K, K512Y, E515Q, D570S, and T571V; bf) K138Q, L142K, Y224K, E239G, V250I, L253A, R306Q, R308L, E375Y, A437G, E466K, D476H, A484E, E508R, D510K, K512Y, E515Q, D570S, and T571V; bg) K135Q, L142K, Y224K, E239G, V250I, L253A, R306Q, R308L, E375Y, A437G, E466K, D476H, A484E, E508R, D510R, K512Y, E515Q, K539E, D570S, and T571V; bh) K131E, K135Q, L142K, Y224K, E239G, V250I, L253A, E375Y, A437G, D476H, A484E, E508R, D510K, K512Y, E515Q, D523R, D570S, and T571V; and bi) L142K, Y224K, E239G, V250I, L253A, R306Q, R308L, E375Y, A437G, E466K, D476H, A484E, E508R, D510K, K512Y, E515Q, and D570M; wherein identification of positions is relative to SEQ ID NO:1. The recombinant polymerase optionally comprises an amino acid sequence selected from the group consisting of: SEQ ID NOs:23-26, SEQ ID NOs:43-46, and SEQ ID NOs:67-128. Additional exemplary mutations and combinations of mutations are described herein or can be formed from those disclosed herein, and polymerases including such combinations are also features of the invention. 
     The recombinant polymerase can be a modified recombinant Φ29 polymerase. Thus, in one class of embodiments, the recombinant polymerase is at least 70% identical to wild-type Φ29 polymerase (SEQ ID NO:1), for example, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, or even at least 99% identical to wild-type Φ29 polymerase (SEQ ID NO:1). As another example, the recombinant polymerase can be a modified recombinant M2Y polymerase. Thus, in one class of embodiments, the recombinant polymerase is at least 70% identical to wild-type M2Y polymerase (SEQ ID NO:2), for example, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, or even at least 99% identical to wild-type M2Y polymerase (SEQ ID NO:2). Optionally, the modified recombinant M2Y polymerase comprises a glutamic acid residue at position 175, an alanine residue at position 256, and/or a methionine residue at position 506, wherein identification of positions is relative to SEQ ID NO:1. In other exemplary classes of embodiments, the recombinant polymerase is a recombinant B103, GA-1, PZA, Φ15, BS32, Nf, G1, Cp-1, PRD1, PZE, SF5, Cp-5, Cp-7, PR4, PR5, PR722, or L17 polymerase. 
     The recombinant polymerase optionally comprises one or more exogenous features, e.g., at the C-terminal and/or N-terminal region of the polymerase, for example, a polyhistidine tag (e.g., a His10 tag) or a biotin ligase recognition sequence. As a few examples, the polymerase can include a C-terminal polyhistidine tag, a C-terminal polyhistidine tag and biotin ligase recognition sequence, two tandem C-terminal biotin ligase recognition sequences, or an N-terminal polyhistidine tag and biotin ligase recognition sequence and a C-terminal polyhistidine tag. 
     The nucleotide analog included in the composition is generally larger than the nucleotides typically used for nucleic acid synthesis and typically includes a label, e.g., a fluorescent label. In one class of embodiments, the analog has a molecular weight of at least 10,000, for example, a molecular weight of at least 20,000, at least 30,000, at least 40,000, at least 50,000, or even at least 60,000, at least 100,000, at least 200,000, or at least 300,000 Da. In one class of embodiments, the analog comprises a polypeptide moiety positioned between a dye moiety and a nucleotide component of the analog. The polypeptide moiety can be, e.g., a tetrameric biotin-binding protein, avidin, streptavidin, neutravidin, tamavidin, or another avidin protein, ubiquitin, or another polypeptide moiety (e.g., a polypeptide comprising at least 60 amino acids, e.g., 60 to 1,000 amino acids, e.g., 80 to 600 amino acids). In one class of embodiments, the analog comprises a multivalent central core element that comprises at least one fluorescent dye. The core is surrounded by multiple intermediate chemical groups, at least one of which includes a shield element, and multiple terminal chemical groups, at least one of which includes a nucleotide. A number of exemplary analogs are described hereinbelow. 
     In one class of embodiments, the composition includes a DNA template, and the polymerase incorporates the nucleotide analog into a copy nucleic acid in response to the DNA template. The composition can be present in a DNA sequencing system, e.g., a zero-mode waveguide (ZMW). The recombinant polymerase can be immobilized on a surface, for example, on a surface of a zero-mode waveguide, preferably in an active form. 
     In one aspect, the invention provides methods of sequencing a DNA template. In the methods, a reaction mixture that includes the DNA template, a replication initiating moiety that complexes with or is integral to the template, one or more nucleotides and/or nucleotide analogs including at least one large analog (e.g., a protein shield analog or other shielded analog or an analog with a molecular weight of at least 10,000), and a recombinant polymerase of the invention (e.g., a recombinant Φ29-type DNA polymerase) is provided. The polymerase is capable of replicating at least a portion of the template using the moiety in a template-dependent polymerization reaction. The reaction mixture is subjected to a polymerization reaction in which the recombinant polymerase replicates at least a portion of the template in a template-dependent manner, whereby the one or more nucleotides and/or nucleotide analogs are incorporated into the resulting DNA. A time sequence of incorporation of the one or more nucleotides and/or nucleotide analogs into the resulting DNA is identified. 
     The nucleotide analogs used in the methods can comprise a first analog and a second analog (and optionally third, fourth, etc. analogs), each of which comprise different fluorescent labels. The different fluorescent labels can optionally be distinguished from one another during the step in which a time sequence of incorporation is identified. Optionally, subjecting the reaction mixture to a polymerization reaction and identifying a time sequence of incorporation are performed in a zero mode waveguide. Essentially all of the features noted for the compositions herein apply to these methods as well, as relevant. 
     In a related aspect, the invention provides methods of making a DNA. In the methods, a reaction mixture is provided that includes a template, a replication initiating moiety that complexes with or is integral to the template, one or more nucleotides and/or nucleotide analogs including at least one large analog (e.g., a protein shield analog or other shielded analog or an analog with a molecular weight of at least 10,000), and a recombinant polymerase of the invention (e.g., a recombinant Φ29-type DNA polymerase). The polymerase is capable of replicating at least a portion of the template using the moiety in a template-dependent polymerase reaction. The mixture is reacted such that the polymerase replicates at least a portion of the template in a template-dependent manner, whereby the one or more nucleotides and/or nucleotide analogs are incorporated into the resulting DNA. The reaction mixture is optionally reacted in a zero mode waveguide. The methods optionally include detecting incorporation of at least one of the nucleotides and/or nucleotide analogs. Essentially all of the features noted for the compositions herein apply to these methods as well, as relevant. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  presents an alignment between the amino acid sequences of wild-type M2Y polymerase (SEQ ID NO:2) and wild-type Φ29 polymerase (SEQ ID NO:1). 
         FIG. 2  depicts the structure of A488dA4P. 
         FIGS. 3A-3B  schematically illustrate an exemplary single molecule sequencing by incorporation process in which the compositions of the invention provide particular advantages. 
         FIG. 4  presents a fluorescence time trace for a ZMW, showing pulses representing incorporation of different nucleotide analogs. The inset schematically illustrates the catalytic cycle for polymerase-mediated extension; the box indicates the portion of the catalytic cycle that corresponds to the pulse when sequencing is performed with phosphate-labeled nucleotide analogs. 
         FIG. 5A  schematically illustrates a thermal inactivation assay. The gapped substrate is listed as SEQ ID NOs: 64 and 65 and the extended strand as SEQ ID NO:66.  FIG. 5B  presents thermal inactivation profiles for six recombinant Φ29 polymerases.  FIG. 5C  presents a bar graph illustrating that addition of a D570E substitution to a variety of recombinant Φ29 polymerases increases their readlength. Binary IT50 values for the polymerases are also shown, over the graph. 
         FIG. 6  shows a view in the vicinity of residue M429 of Φ29 polymerase. Residues from the fingers domain are shown as sticks, and the location of the incoming nucleotide is indicated by an arrow. 
         FIG. 7  provides exemplary polymerase mutations and combinations thereof in accordance with the invention. Positions of the mutations are identified relative to a wild-type Φ29 DNA polymerase (SEQ ID NO:1) where the name of the polymerase includes “Phi29” or relative to a wild-type M2Y polymerase (SEQ ID NO:2) where the name of the polymerase includes “M2.” 
         FIG. 8  provides exemplary polymerase mutations and combinations thereof in accordance with the invention. Positions of the mutations are identified relative to a wild-type Φ29 DNA polymerase (SEQ ID NO:1) where the name of the polymerase includes “Phi29” or relative to a wild-type M2Y polymerase (SEQ ID NO:2) where the name of the polymerase includes “M2.” 
         FIG. 9  provides exemplary polymerase mutations and combinations thereof in accordance with the invention. Positions of the mutations are identified relative to a wild-type Φ29 DNA polymerase (SEQ ID NO:1) where the name of the polymerase includes “Phi29” or relative to a wild-type M2Y polymerase (SEQ ID NO:2) where the name of the polymerase includes “M2.” 
       Schematic figures are not necessarily to scale. 
       Definitions 
       Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. The following definitions supplement those in the art and are directed to the current application and are not to be imputed to any related or unrelated case, e.g., to any commonly owned patent or application. Although any methods and materials similar or equivalent to those described herein can be used in the practice for testing of the present invention, the preferred materials and methods are described herein. Accordingly, the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting. 
       As used in this specification and the appended claims, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a protein” includes a plurality of proteins; reference to “a cell” includes mixtures of cells, and the like. 
       The term “about” as used herein indicates the value of a given quantity varies by +/−10% of the value, or optionally +/−5% of the value, or in some embodiments, by +/−1% of the value so described. 
       The term “nucleic acid” or “polynucleotide” encompasses any physical string of monomer units that can be corresponded to a string of nucleotides, including a polymer of nucleotides (e.g., a typical DNA or RNA polymer), PNAs, modified oligonucleotides (e.g., oligonucleotides comprising nucleotides that are not typical to biological RNA or DNA, such as 2′-O-methylated oligonucleotides), and the like. A nucleic acid can be e.g., single-stranded or double-stranded. Unless otherwise indicated, a particular nucleic acid sequence of this invention encompasses complementary sequences, in addition to the sequence explicitly indicated. 
       A “polypeptide” is a polymer comprising two or more amino acid residues (e.g., a peptide or a protein). The polymer can additionally comprise non-amino acid elements such as labels, quenchers, blocking groups, or the like and can optionally comprise modifications such as glycosylation, biotinylation, or the like. The amino acid residues of the polypeptide can be natural or non-natural and can be unsubstituted, unmodified, substituted or modified. 
       An “amino acid sequence” is a polymer of amino acid residues (a protein, polypeptide, etc.) or a character string representing an amino acid polymer, depending on context. 
       A “polynucleotide sequence” or “nucleotide sequence” is a polymer of nucleotides (an oligonucleotide, a DNA, a nucleic acid, etc.) or a character string representing a nucleotide polymer, depending on context. From any specified polynucleotide sequence, either the given nucleic acid or the complementary polynucleotide sequence (e.g., the complementary nucleic acid) can be determined. 
       Numbering of a given amino acid or nucleotide polymer “corresponds to numbering of” or is “relative to” a selected amino acid polymer or nucleic acid when the position of any given polymer component (amino acid residue, incorporated nucleotide, etc.) is designated by reference to the same residue position in the selected amino acid or nucleotide polymer, rather than by the actual position of the component in the given polymer. Similarly, identification of a given position within a given amino acid or nucleotide polymer is “relative to” a selected amino acid or nucleotide polymer when the position of any given polymer component (amino acid residue, incorporated nucleotide, etc.) is designated by reference to the residue name and position in the selected amino acid or nucleotide polymer, rather than by the actual name and position of the component in the given polymer. Correspondence of positions is typically determined by aligning the relevant amino acid or polynucleotide sequences. For example, residue K221 of wild-type M2Y polymerase (SEQ ID NO:2) is identified as position Y224 relative to wild-type Φ29 polymerase (SEQ ID NO:1); see, e.g., the alignment shown in  FIG. 1 . Similarly, residue L138 of wild-type M2Y polymerase (SEQ ID NO:2) is identified as position V141 relative to wild-type Φ29 polymerase (SEQ ID NO:1), and an L138K substitution in the M2Y polymerase is thus identified as a V141K substitution relative to SEQ ID NO:1. Amino acid positions herein are generally identified relative to SEQ ID NO:1 unless explicitly indicated otherwise. 
       The term “recombinant” indicates that the material (e.g., a nucleic acid or a protein) has been artificially or synthetically (non-naturally) altered by human intervention. The alteration can be performed on the material within, or removed from, its natural environment or state. For example, a “recombinant nucleic acid” is one that is made by recombining nucleic acids, e.g., during cloning, DNA shuffling or other procedures, or by chemical or other mutagenesis; a “recombinant polypeptide” or “recombinant protein” is, e.g., a polypeptide or protein which is produced by expression of a recombinant nucleic acid. 
       A “Φ29-type DNA polymerase” (or “phi29-type DNA polymerase”) is a DNA polymerase from the Φ29 phage or from one of the related phages that, like Φ29, contain a terminal protein used in the initiation of DNA replication. Φ29-type DNA polymerases are homologous to the Φ29 DNA polymerase (e.g., as listed in SEQ ID NO:1); examples include the B103, GA-1, PZA, Φ15, BS32, M2Y (also known as M2), Nf, G1, Cp-1, PRD1, PZE, SFS, Cp-5, Cp-7, PR4, PR5, PR722, L17, and AV-1 DNA polymerases, as well as chimeras thereof. A modified recombinant Φ29-type DNA polymerase includes one or more mutations relative to naturally-occurring wild-type Φ29-type DNA polymerases, for example, one or more mutations that increase stability, increase readlength, alter interaction with and/or incorporation of nucleotide analogs, enhance accuracy, increase phototolerance, and/or alter another polymerase property, and may include additional alterations or modifications over the wild-type Φ29-type DNA polymerase, such as one or more deletions, insertions, and/or fusions of additional peptide or protein sequences (e.g., for immobilizing the polymerase on a surface or otherwise tagging the polymerase enzyme). 
       A variety of additional terms are defined or otherwise characterized herein. 
     
    
    
     DETAILED DESCRIPTION 
     Among other aspects, the present invention provides new recombinant polymerases. A recombinant polymerase of the invention, e.g., a recombinant Φ29-type DNA polymerase, typically includes one or more mutations (e.g., amino acid substitutions, deletions, or insertions) as compared to a reference polymerase, e.g., a wild-type Φ29-type polymerase. Depending on the particular mutation or combination of mutations, the polymerase exhibits one or more properties that find use in, e.g., single molecule sequencing applications or nucleic acid amplification. Such polymerases incorporate nucleotides and/or nucleotide analogs, for example, dye labeled phosphate labeled analogs, into a growing template copy during DNA amplification. These polymerases are modified such that they have one or more desirable properties, for example, improved sequencing performance with large nucleotide analogs, increased readlength, increased thermostability, increased resistance to photodamage, decreased branching fraction formation when incorporating the relevant analogs, improved DNA-polymerase stability or processivity, increased cosolvent resistance, reduced exonuclease activity, increased yield, altered cofactor selectivity, improved accuracy, increased or decreased speed, and/or altered kinetic properties (e.g., a reduction in the rate of one or more steps of the polymerase kinetic cycle, resulting from, e.g., enhanced interaction of the polymerase with nucleotide analog, enhanced metal coordination, etc.) as compared to a corresponding wild-type or other parental polymerase (e.g., a polymerase from which the modified recombinant polymerase of the invention was derived, e.g., by mutation), as well as other features that will become apparent upon a complete review of the present disclosure. The polymerases of the invention can also include any of the additional features for improved specificity, processivity, retention time, surface stability, analog incorporation, and/or the like noted herein. The polymerases can include one or more exogenous or heterologous features, e.g., at the N- and/or C-terminal regions of the polymerase. Such features find use not only for purification of the recombinant polymerase and/or immobilization of the polymerase to a substrate, but can also alter one or more properties of the polymerase. 
     These new polymerases are particularly well suited to DNA amplification and/or sequencing applications, particularly sequencing protocols that include detection in real time of the incorporation of labeled analogs into DNA amplicons. As a few examples, increased readlength can produce longer sequence reads that facilitate scaffolding of sequences obtained from shorter reads during genome assembly, increased phototolerance can prolong useful life of the polymerase under assay conditions, and altered rates, reduced or eliminated exonuclease activity, decreased branching fraction, improved complex stability, altered metal cofactor selectivity, or the like can facilitate discrimination of nucleotide incorporation events from non-incorporation events such as transient binding of a mismatched nucleotide in the active site of the complex, improve processivity, and/or facilitate detection of incorporation events. 
     Exemplary polymerases include a recombinant Φ29-type DNA polymerase that comprises a mutation at one or more positions selected from the group consisting of C11, L44, A49, Q99, C106, K114, L123, K131, A134, K135, K138, V141, L142, Y148, E175, Y224, D235, E239, V250, L253, A256, C290, R306, R308, K311, K337, Y369, E375, M429, A437, T441, C448, C455, E466, V475, D476, A484, H485, S487, E508, D510, K512, L513, E515, D523, I524, F526, K536, K539, P558, D570, and T571, where identification of positions is relative to wild-type Φ29 polymerase (SEQ ID NO:1). Optionally, the polymerase comprises mutations at two, three, four, five, six, seven, eight, nine, ten, or even eleven or more of these positions. For example, the polymerase can include a mutation at position E375, a mutation at position K512, and a mutation at one or more additional positions, e.g., as described herein. Similarly, for example, the polymerase can comprise mutations at positions 375, 512, and 253, positions 375, 512, and 484, positions 253 and 484, positions 375, 512, 253, and 484, positions 375, 512, 253, 484, and 510, positions 253 and 437, positions 253 and 250, positions 253, 437, and 250, positions 148 and 570, positions 239, 253, 375, 437, 484, 510, 512, and 515, positions 224, 239, 253, 375, 437, 484, 510, 512, and 515, positions 148, 224, 239, 253, 375, 437, 484, 510, 512, and 515, or positions 131, 224, 239, 253, 375, 437, 484, 510, 512, and 515, and a mutation at one or more additional positions, e.g., as described herein, where identification of positions is relative to wild-type Φ29 polymerase (SEQ ID NO:1). A number of exemplary substitutions at these (and other) positions are described herein. 
     As a few examples, a mutation at E375 can comprise an amino acid substitution selected from the group consisting of E375Y (i.e., a tyrosine residue is present at position E375 where identification of positions is relative to SEQ ID NO:1), E375F, E375R, E375Q, E375H, E375L, E375A, E375K, E375S, E375T, E375C, E375G, and E375N; a mutation at position K512 can comprise an amino acid substitution selected from the group consisting of K512Y, K512F, K512I, K512M, K512C, K512E, K512G, K512H, K512N, K512Q, K512R, K512V, and K512H; a mutation at position L253 can comprise an amino acid substitution selected from the group consisting of L253A, L253H, L253S, and L253C; a mutation at position A484 can comprise an A484E substitution; and/or a mutation at position D510 can comprise a D510K or D510S substitution. Other exemplary substitutions include, e.g., C11A, L44A, A49E, Q99P, Q99I, Q99W, Q99Y, C106S, K114R, L123K, L123Y, L123R, L123Q, L123A, K131E, A134S, K135Q, K135S, K138Q, K138C, K138A, V141K, L142K, Y148I, Y224K, D235E, E239G, V250A, V250I, A256S, C290F, R306Q, R308L, K311E, K337C, K337Q, Y369E, M429A, A437G, A437N, T441I, C448V, C455A, E466K, V475I, D476H, H485Q, S487A, E508K, E508R, L513K, E515Q, D523R, I524S, I524T, F526L, K536Q, K536T, K536E, K539Q, K539E, P558A, P558F, D570E, D570N, D570S, D570T, D570H, D570L, D570M, D570V, D570I, D570W, D570Y, D570F, D570G, D570Q, D570K, D570R, D570P, D570A, D570C, T571V, and T571A; additional substitutions are described herein. 
     The polymerase mutations and mutational strategies noted herein can be combined with each other and with essentially any other available mutations and mutational strategies to confer additional improvements in, e.g., nucleotide analog specificity, enzyme processivity, improved retention time of labeled nucleotides in polymerase-DNA-nucleotide complexes, phototolerance, and the like. For example, the mutations and mutational strategies herein can be combined with those taught in, e.g., WO 2007/076057 “Polymerases for Nucleotide Analogue Incorporation” by Hanzel et al., WO 2008/051530 “Polymerase Enzymes and Reagents for Enhanced Nucleic Acid Sequencing” by Rank et al., US patent application publication 2010-0075332 “Engineering Polymerases and Reaction Conditions for Modified Incorporation Properties” by Pranav Patel et al., US patent application publication 2010-0093555 “Enzymes Resistant to Photodamage” by Keith Bjornson et al., US patent application publication 2010-0112645 “Generation of Modified Polymerases for Improved Accuracy in Single Molecule Sequencing” by Sonya Clark et al., US patent application publication 2011-0189659 “Generation of Modified Polymerases for Improved Accuracy in Single Molecule Sequencing” by Sonya Clark et al., US patent application publication 2012-0034602 “Recombinant Polymerases For Improved Single Molecule Sequencing” by Robin Emig et al., and U.S. patent application Ser. No. 13/756,113 filed Jan. 31, 2013 by Satwik Kamtekar et al. and entitled “Recombinant Polymerases with Increased Phototolerance.” This combination of mutations/mutational strategies can be used to impart several simultaneous improvements to a polymerase (e.g., enhanced utility with large analogs, increased readlength, increased phototolerance, decreased branching fraction formation, improved specificity, improved processivity, altered rates, improved retention time, improved stability of the closed complex, tolerance for a particular metal cofactor, etc.). In addition, polymerases can be further modified for application-specific reasons, such as to improve activity of the enzyme when bound to a surface, as taught, e.g., in WO 2007/075987 “Active Surface Coupled Polymerases” by Hanzel et al. and WO 2007/075873 “Protein Engineering Strategies to Optimize Activity of Surface Attached Proteins” by Hanzel et al., or to include purification or handling tags as is taught in the cited references and as is common in the art. Similarly, the modified polymerases described herein can be employed in combination with other strategies to improve polymerase performance, for example, reaction conditions for controlling polymerase rate constants such as taught in US patent application publication US 2009-0286245 entitled “Two slow-step polymerase enzyme systems and methods.” 
     Also taught are approaches for modifying polymerases to enhance one or more properties exhibited by the polymerases or to confer an additional property not provided by a starting combination of mutations. For example, provided below are approaches for obtaining polymerases with enhanced utility with large nucleotide analogs, increased readlength, increased thermostability, and improved ability to detect base modifications. 
     DNA Polymerases 
     DNA polymerases that can be modified to have increased readlength, greater thermostability, and/or other desirable properties as described herein are generally available. DNA polymerases are sometimes classified into six main groups based upon various phylogenetic relationships, e.g., with  E. coli  Pol I (class A),  E. coli  Pol II (class B),  E. coli  Pol III (class C), Euryarchaeotic Pol II (class D), human Pol beta (class X), and  E. coli  UmuC/DinB and eukaryotic RAD30/ Xeroderma pigmentosum  variant (class Y). For a review of recent nomenclature, see, e.g., Burgers et al. (2001) “Eukaryotic DNA polymerases: proposal for a revised nomenclature” J Biol Chem. 276(47):43487-90. For a review of polymerases, see, e.g., Hübscher et al. (2002) “Eukaryotic DNA Polymerases” Annual Review of Biochemistry Vol. 71: 133-163; Alba (2001) “Protein Family Review: Replicative DNA Polymerases” Genome Biology 2(1):reviews 3002.1-3002.4; and Steitz (1999) “DNA polymerases: structural diversity and common mechanisms” J Biol Chem 274:17395-17398. The basic mechanisms of action for many polymerases have been determined. The sequences of literally hundreds of polymerases are publicly available, and the crystal structures for many of these have been determined or can be inferred based upon similarity to solved crystal structures for homologous polymerases. For example, the crystal structure of Φ29, a preferred type of parental enzyme to be modified according to the invention, is available. 
     Many such polymerases that are suitable for modification are available, e.g., for use in sequencing, labeling, and amplification technologies. For example, human DNA Polymerase Beta is available from R&amp;D systems. DNA polymerase I is available from Epicenter, GE Health Care, Invitrogen, New England Biolabs, Promega, Roche Applied Science, Sigma Aldrich, and many others. The Klenow fragment of DNA Polymerase I is available in both recombinant and protease digested versions, from, e.g., Ambion, Chimerx, eEnzyme LLC, GE Health Care, Invitrogen, New England Biolabs, Promega, Roche Applied Science, Sigma Aldrich and many others. Φ29 DNA polymerase is available from e.g., Epicentre. Poly A polymerase, reverse transcriptase, Sequenase, SP6 DNA polymerase, T4 DNA polymerase, T7 DNA polymerase, and a variety of thermostable DNA polymerases (Taq, hot start, titanium Taq, etc.) are available from a variety of these and other sources. Recent commercial DNA polymerases include Phusion™ High-Fidelity DNA Polymerase, available from New England Biolabs; GoTaq® Flexi DNA Polymerase, available from Promega; RepliPHI™ Φ29 DNA Polymerase, available from Epicentre Biotechnologies; PfuUltra™ Hotstart DNA Polymerase, available from Stratagene; KOD HiFi DNA Polymerase, available from Novagen; and many others. Biocompare(dot)com provides comparisons of many different commercially available polymerases. 
     DNA polymerases that are preferred substrates for mutation to enhance performance with large nucleotide analogs, increase readlength, improve thermostability, improve detection of base modifications, increase phototolerance, reduce reaction rates, reduce or eliminate exonuclease activity, alter metal cofactor selectivity, and/or alter one or more other property described herein include Taq polymerases, exonuclease deficient Taq polymerases,  E. coli  DNA Polymerase 1, Klenow fragment, reverse transcriptases, Φ29 related polymerases including wild type Φ29 polymerase and derivatives of such polymerases such as exonuclease deficient forms, T7 DNA polymerase, T5 DNA polymerase, RB69 polymerase, etc. 
     In one aspect, the polymerase that is modified is a Φ29-type DNA polymerase. For example, the modified recombinant DNA polymerase can be homologous to a wild-type or exonuclease deficient Φ29 DNA polymerase, e.g., as described in U.S. Pat. Nos. 5,001,050, 5,198,543, or 5,576,204. Similarly, the modified recombinant DNA polymerase can be homologous to another Φ29-type DNA polymerase, such as B103, GA-1, PZA, Φ15, BS32, M2Y (also known as M2), Nf, G1, Cp-1, PRD1, PZE, SFS, Cp-5, Cp-7, PR4, PR5, PR722, L17, AV-1, Φ21, or the like. For nomenclature, see also, Meijer et al. (2001) “Φ29 Family of Phages” Microbiology and Molecular Biology Reviews, 65(2):261-287. See, e.g., SEQ ID NO:1 for the amino acid sequence of wild-type Φ29 polymerase, SEQ ID NO:2 for the amino acid sequence of wild-type M2Y polymerase, SEQ ID NO:3 for the amino acid sequence of wild-type B103 polymerase, SEQ ID NO:4 for the amino acid sequence of wild-type GA-1 polymerase, SEQ ID NO:5 for the amino acid sequence of wild-type AV-1 polymerase, and SEQ ID NO:6 for the amino acid sequence of wild-type CP-1 polymerase. 
     In addition to wild-type polymerases, chimeric polymerases made from a mosaic of different sources can be used. For example, Φ29-type polymerases made by taking sequences from more than one parental polymerase into account can be used as a starting point for mutation to produce the polymerases of the invention. Chimeras can be produced, e.g., using consideration of similarity regions between the polymerases to define consensus sequences that are used in the chimera, or using gene shuffling technologies in which multiple Φ29-related polymerases are randomly or semi-randomly shuffled via available gene shuffling techniques (e.g., via “family gene shuffling”; see Crameri et al. (1998) “DNA shuffling of a family of genes from diverse species accelerates directed evolution” Nature 391:288-291; Clackson et al. (1991) “Making antibody fragments using phage display libraries” Nature 352:624-628; Gibbs et al. (2001) “Degenerate oligonucleotide gene shuffling (DOGS): a method for enhancing the frequency of recombination with family shuffling” Gene 271:13-20; and Hiraga and Arnold (2003) “General method for sequence-independent site-directed chimeragenesis: J. Mol. Biol. 330:287-296). In these methods, the recombination points can be predetermined such that the gene fragments assemble in the correct order. However, the combinations, e.g., chimeras, can be formed at random. For example, using methods described in Clarkson et al., five gene chimeras, e.g., comprising segments of a Phi29 polymerase, a PZA polymerase, a M2 polymerase, a B103 polymerase, and a GA-1 polymerase, can be generated. Appropriate mutations to enhance performance with large analogs, increase readlength, improve thermostability, and/or alter another desirable property as described herein can be introduced into the chimeras. 
     Available DNA polymerase enzymes have also been modified in any of a variety of ways, e.g., to reduce or eliminate exonuclease activities (many native DNA polymerases have a proof-reading exonuclease function that interferes with, e.g., sequencing applications), to simplify production by making protease digested enzyme fragments such as the Klenow fragment recombinant, etc. As noted, polymerases have also been modified to confer improvements in specificity, processivity, and retention time of labeled nucleotides in polymerase-DNA-nucleotide complexes (e.g., WO 2007/076057 “Polymerases for Nucleotide Analogue Incorporation” by Hanzel et al. and WO 2008/051530 “Polymerase Enzymes and Reagents for Enhanced Nucleic Acid Sequencing” by Rank et al.), to alter branching fraction and translocation (e.g., US patent application publication 2010-0075332 by Pranav Patel et al. entitled “Engineering Polymerases and Reaction Conditions for Modified Incorporation Properties”), to increase photostability (e.g., US patent application publication 2010-0093555 “Enzymes Resistant to Photodamage” by Keith Bjornson et al. and U.S. patent application Ser. No. 13/756,113 filed Jan. 31, 2013 by Satwik Kamtekar et al. and entitled “Recombinant Polymerases with Increased Phototolerance”), to slow one or more catalytic steps during the polymerase kinetic cycle, increase closed complex stability, decrease branching fraction, alter cofactor selectivity, and increase yield, thermostability, accuracy, speed, and readlength (e.g., US patent application publication 2010-0112645 “Generation of Modified Polymerases for Improved Accuracy in Single Molecule Sequencing” by Sonya Clark et al., US patent application publication 2011-0189659 “Generation of Modified Polymerases for Improved Accuracy in Single Molecule Sequencing” by Sonya Clark et al., and US patent application publication 2012-0034602 “Recombinant Polymerases For Improved Single Molecule Sequencing” by Robin Emig et al.), and to improve surface-immobilized enzyme activities (e.g., WO 2007/075987 Active Surface Coupled Polymerases by Hanzel et al. and WO 2007/075873 Protein Engineering Strategies to Optimize Activity of Surface Attached Proteins by Hanzel et al.). Any of these available polymerases can be modified in accordance with the invention. 
     Nucleotide Analogs 
     As discussed, various polymerases of the invention can incorporate one or more nucleotide analogs into a growing oligonucleotide chain. Upon incorporation, the analog can leave a residue that is the same as or different than a natural nucleotide in the growing oligonucleotide (the polymerase can incorporate any non-standard moiety of the analog, or can cleave it off during incorporation into the oligonucleotide). A “nucleotide analog” herein is a compound, that, in a particular application, functions in a manner similar or analogous to a naturally occurring nucleoside triphosphate (a “nucleotide”), and does not otherwise denote any particular structure. A nucleotide analog is an analog other than a standard naturally occurring nucleotide, i.e., other than A, G, C, T, or U, though upon incorporation into the oligonucleotide, the resulting residue in the oligonucleotide can be the same as (or different from) an A, G, C, T, or U residue. 
     In one useful aspect of the invention, nucleotide analogs can also be modified to achieve any of the improved properties desired. For example, various linkers or other substituents can be incorporated into analogs that have the effect of reducing branching fraction, improving processivity, or altering rates. Modifications to the analogs can include extending the phosphate chains, e.g., to include a tetra-, penta-, hexa- or heptaphosphate group, and/or adding chemical linkers to extend the distance between the nucleotide base and the dye molecule, e.g., a fluorescent dye molecule. Substitution of one or more non-bridging oxygen in the polyphosphate, for example with S or BH 3 , can change the polymerase reaction kinetics, e.g., to achieve a system having two slow steps as described hereinbelow. Optionally, one or more, two or more, three or more, or four or more non-bridging oxygen atoms in the polyphosphate group of the analog has an S substituted for an O. While not being bound by theory, it is believed that the properties of the nucleotide, such as the metal chelation properties, electronegativity, or steric properties, can be altered by substitution of the non-bridging oxygen(s). 
     Many nucleotide analogs are available and can be incorporated by the polymerases of the invention. These include analog structures with core similarity to naturally occurring nucleotides, such as those that comprise one or more substituent on a phosphate, sugar, or base moiety of the nucleoside or nucleotide relative to a naturally occurring nucleoside or nucleotide. In one embodiment, the nucleotide analog includes three phosphate containing groups; for example, the analog can be a labeled nucleoside triphosphate analog and/or an α-thiophosphate nucleotide analog having three phosphate groups. In one embodiment, a nucleotide analog can include one or more extra phosphate containing groups, relative to a nucleoside triphosphate. For example, a variety of nucleotide analogs that comprise, e.g., from 4-6 or more phosphates are described in detail in US patent application publication 2007-0072196, incorporated herein by reference in its entirety for all purposes. Other exemplary useful analogs, including tetraphosphate and pentaphosphate analogs, are described in U.S. Pat. No. 7,041,812, incorporated herein by reference in its entirety for all purposes. 
     For example, the analog can include a labeled compound of the formula: 
     
       
         
         
             
             
         
       
     
     wherein B is a nucleobase (and optionally includes a label); S is selected from a sugar moiety, an acyclic moiety or a carbocyclic moiety (and optionally includes a label); L is an optional detectable label; R 1  is selected from O and S; R 2 , R 3  and R 4  are independently selected from O, NH, S, methylene, substituted methylene, C(O), C(CH 2 ), CNH 2 , CH 2 CH 2 , and C(OH)CH 2 R where R is 4-pyridine or 1-imidazole, provided that R 4  may additionally be selected from 
     
       
         
         
             
             
         
       
     
     R 5 , R 6 , R 7 , R 8 , R 11  and R 13  are, when present, each independently selected from O, BH 3 , and S; and R 9 , R 10  and R 12  are independently selected from O, NH, S, methylene, substituted methylene, CNH 2 , CH 2 CH 2 , and C(OH)CH 2 R where R is 4-pyridine or 1-imidazole. In some cases, phosphonate analogs may be employed as the analogs, e.g., where one of R 2 , R 3 , R 4 , R 9 , R 10  or R 12  are not O, e.g., they are methyl etc. See, e.g., US patent application publication 2007-0072196, previously incorporated herein by reference in its entirety for all purposes. 
     The base moiety incorporated into the analog is generally selected from any of the natural or non-natural nucleobases or nucleobase analogs, including, e.g., purine or pyrimidine bases that are routinely found in nucleic acids and available nucleic acid analogs, including adenine, thymine, guanine, cytidine, uracil, and in some cases, inosine. As noted, the base optionally includes a label moiety. For convenience, nucleotides and nucleotide analogs are generally referred to based upon their relative analogy to naturally occurring nucleotides. As such, an analog that operates, functionally, like adenosine triphosphate, may be generally referred to herein by the shorthand letter A. Likewise, the standard abbreviations of T, G, C, U and I, may be used in referring to analogs of naturally occurring nucleosides and nucleotides typically abbreviated in the same fashion. In some cases, a base may function in a more universal fashion, e.g., functioning like any of the purine bases in being able to hybridize with any pyrimidine base, or vice versa. The base moieties used in the present invention may include the conventional bases described herein or they may include such bases substituted at one or more side groups, or other fluorescent bases or base analogs, such as 1,N6 ethenoadenosine or pyrrolo C, in which an additional ring structure renders the B group neither a purine nor a pyrimidine. For example, in certain cases, it may be desirable to substitute one or more side groups of the base moiety with a labeling group or a component of a labeling group, such as one of a donor or acceptor fluorophore, or other labeling group. Examples of labeled nucleobases and processes for labeling such groups are described in, e.g., U.S. Pat. Nos. 5,328,824 and 5,476,928, each of which is incorporated herein by reference in its entirety for all purposes. 
     In the analogs, the S group is optionally a sugar moiety that provides a suitable backbone for a synthesizing nucleic acid strand. For example, the sugar moiety is optionally selected from a D-ribosyl, 2′ or 3′ D-deoxyribosyl, 2′,3′-D-dideoxyribosyl, 2′,3′-D-didehydrodideoxyribosyl, 2′ or 3′ alkoxyribosyl, 2′ or 3′ aminoribosyl, 2′ or 3′ mercaptoribosyl, 2′ or 3′ alkothioribosyl, acyclic, carbocyclic or other modified sugar moieties. A variety of carbocyclic or acyclic moieties can be incorporated as the “S” group in place of a sugar moiety, including, e.g., those described in U.S. Patent Application Publication No. 2003/0124576, which is incorporated herein by reference in its entirety for all purposes. 
     For most cases, the phosphorus containing chain in the analogs, e.g., a triphosphate in conventional NTPs, is preferably coupled to the 5′ hydroxyl group, as in natural nucleoside triphosphates. However, in some cases, the phosphorus containing chain is linked to the S group by the 3′ hydroxyl group. 
     L generally refers to a detectable labeling group that is coupled to the terminal phosphorus atom via the R 4  (or R 10  or R 12  etc.) group. The labeling groups employed in the analogs of the invention may comprise any of a variety of detectable labels. Detectable labels generally denote a chemical moiety that provides a basis for detection of the analog compound separate and apart from the same compound lacking such a labeling group. Examples of labels include, e.g., optical labels, e.g., labels that impart a detectable optical property to the analog, electrochemical labels, e.g., labels that impart a detectable electrical or electrochemical property to the analog, and physical labels, e.g., labels that impart a different physical or spatial property to the analog, e.g., a mass tag or molecular volume tag. In some cases individual labels or combinations may be used that impart more than one of the aforementioned properties to the analogs of the invention. 
     Optionally, the labeling groups incorporated into the analogs comprise optically detectable moieties, such as luminescent, chemiluminescent, fluorescent, fluorogenic, chromophoric and/or chromogenic moieties, with fluorescent and/or fluorogenic labels being preferred. A variety of different label moieties are readily employed in nucleotide analogs. Such groups include, e.g., fluorescein labels, rhodamine labels, cyanine labels (i.e., Cy3, Cy5, and the like, generally available from the Amersham Biosciences division of GE Healthcare), and the Alexa family of fluorescent dyes and other fluorescent and fluorogenic dyes available from Molecular Probes/Invitrogen, Inc. and described in ‘The Handbook—A Guide to Fluorescent Probes and Labeling Technologies, Eleventh Edition’ (2010) (available from Invitrogen, Inc./Molecular Probes). A variety of other fluorescent and fluorogenic labels for use with nucleoside polyphosphates, and which would be applicable to the nucleotide analogs incorporated by the polymerases of the present invention, are described in, e.g., U.S. Patent Application Publication No. 2003/0124576, previously incorporated herein by reference in its entirety for all purposes. 
     Thus, in one illustrative example, the analog can be a phosphate analog (e.g., an analog that has more than the typical number of phosphates found in nucleoside triphosphates) that includes, e.g., an Alexa dye label. For example, an Alexa488 dye can be labeled on a delta phosphate of a tetraphosphate analog (denoted, e.g., A488dC4P or A488dA4P, shown in  FIG. 2 , for the Alexa488 labeled tetraphosphate analogs of C and A, respectively), or an Alexa568 or Alexa633 dye can be used (e.g., A568dC4P and A633dC4P, respectively, for labeled tetraphosphate analogs of C or A568dT6P for a labeled hexaphosphate analog of T), or an Alexa546 dye can be used (e.g., A546dG4P), or an Alexa594 dye can be used (e.g., A594dT4P). As additional examples, an Alexa555 dye (e.g., A555dC6P or A555dA6P), an Alexa 647 dye (e.g., A647dG6P), an Alexa 568 dye (e.g., A568dT6P), and/or an Alexa660 dye (e.g., A660dA6P or A660dC6P) can be used in, e.g., single molecule sequencing. Similarly, to facilitate color separation, a pair of fluorophores exhibiting FRET (fluorescence resonance energy transfer) can be labeled on a delta phosphate of a tetraphosphate analog (denoted, e.g., FAM-amb-A532dG4P or FAM-amb-A594dT4P). 
     As noted above, an analog can include a linker that extends the distance between the nucleotide base and the label moiety, e.g., a fluorescent dye moiety. Exemplary linkers and analogs are described in U.S. Pat. No. 7,968,702. Similarly, a protein or other moiety can be employed to provide spacing and/or shielding between the base and the label, e.g., as described in U.S. patent application 61/599,149, U.S. patent application Ser. No. 13/767,619 “Polymerase Enzyme Substrates with Protein Shield” filed Feb. 14, 2013, and U.S. patent application 61/862,502 “Protected Fluorescent Reagent Compounds” filed Aug. 5, 2013. Suitable polymerase substrates optionally include two or more nucleoside polyphosphates and/or two or more label moieties, e.g., as described in U.S. patent application 61/599,149 “Polymerase Enzyme Substrates with Protein Shield,” U.S. patent application Ser. No. 13/767,619 “Polymerase Enzyme Substrates with Protein Shield,” U.S. patent application 61/862,502 “Protected Fluorescent Reagent Compounds,” and US patent application publication 2009-0208957 Alternate Labeling Strategies for Single Molecule Sequencing. 
     Additional details regarding labels, analogs, and methods of making such analogs can be found in US patent application publication 2007-0072196,WO 2007/041342 Labeled Nucleotide Analogs and Uses Therefor, WO 2009/114182 Labeled Reactants and Their Uses, US patent application publication 2009-0208957 Alternate Labelling Strategies for Single Molecule Sequencing, U.S. patent application Ser. No. 13/218,412 Functionalized Cyanine Dyes, U.S. patent application Ser. No. 13/218,395 Functionalized Cyanine Dyes, U.S. patent application Ser. No. 13/218,428 Cyanine Dyes, U.S. patent application Ser. No. 13/218,382 Scaffold-Based Polymerase Enzyme Substrates, US patent application publication 2010-0167299 Phospholink Nucleotides for Sequencing Applications, US patent application publication 2010-0152424 Modular Nucleotide Compositions and Uses Therefor, U.S. patent application 61/599,149 Polymerase Enzyme Substrates with Protein Shield, U.S. patent application Ser. No. 13/767,619 “Polymerase Enzyme Substrates with Protein Shield,” and U.S. patent application 61/862,502 “Protected Fluorescent Reagent Compounds,” each of which is incorporated herein by reference in its entirety for all purposes. 
     Applications for Enhanced Nucleic Acid Amplification and Sequencing 
     Polymerases of the invention, e.g., modified recombinant polymerases, are optionally used in combination with nucleotides and/or nucleotide analogs and nucleic acid templates (e.g., DNA, RNA, or hybrids, analogs, derivatives, or mimetics thereof) to copy the template nucleic acid. That is, a mixture of the polymerase, nucleotides/analogs, and optionally other appropriate reagents, the template and a replication initiating moiety (e.g., primer) is reacted such that the polymerase synthesizes nucleic acid (e.g., extends the primer) in a template-dependent manner The replication initiating moiety can be a standard oligonucleotide primer, or, alternatively, a component of the template, e.g., the template can be a self-priming single stranded DNA, a nicked double stranded DNA, or the like. Similarly, a terminal protein can serve as an initiating moiety. At least one nucleotide analog can be incorporated into the DNA. The template DNA can be a linear or circular DNA, and in certain applications, is desirably a circular template (e.g., for rolling circle replication or for sequencing of circular templates). Optionally, the composition can be present in an automated DNA replication and/or sequencing system. 
     Incorporation of labeled nucleotide analogs by the polymerases of the invention is particularly useful in a variety of different nucleic acid analyses, including real-time monitoring of DNA polymerization. The label can itself be incorporated, or more preferably, can be released during incorporation of the analog. For example, analog incorporation can be monitored in real time by monitoring label release during incorporation of the analog by the polymerase. The portion of the analog that is incorporated can be the same as a natural nucleotide, or can include features of the analog that differ from a natural nucleotide. 
     In general, label incorporation or release can be used to indicate the presence and composition of a growing nucleic acid strand, e.g., providing evidence of template replication/amplification and/or sequence of the template. Signaling from the incorporation can be the result of detecting labeling groups that are liberated from the incorporated analog, e.g., in a solid phase assay, or can arise upon the incorporation reaction. For example, in the case of FRET labels where a bound label is quenched and a free label is not, release of a label group from the incorporated analog can give rise to a fluorescent signal. Alternatively, the enzyme may be labeled with one member of a FRET pair proximal to the active site, and incorporation of an analog bearing the other member will allow energy transfer upon incorporation. The use of enzyme bound FRET components in nucleic acid sequencing applications is described, e.g., in U.S. Patent Application Publication No. 2003/0044781, incorporated herein by reference. 
     In one example reaction of interest, a polymerase reaction can be isolated within an extremely small observation volume that effectively results in observation of individual polymerase molecules. As a result, the incorporation event provides observation of an incorporating nucleotide analog that is readily distinguishable from non-incorporated nucleotide analogs. In a preferred aspect, such small observation volumes are provided by immobilizing the polymerase enzyme within an optical confinement, such as a Zero Mode Waveguide (ZMW). For a description of ZMWs and their application in single molecule analyses, and particularly nucleic acid sequencing, see, e.g., U.S. Patent Application Publication No. 2003/0044781 and U.S. Pat. No. 6,917,726, each of which is incorporated herein by reference in its entirety for all purposes. See also Levene et al. (2003) “Zero-mode waveguides for single-molecule analysis at high concentrations” Science 299:682-686, Eid et al. (2009) “Real-time DNA sequencing from single polymerase molecules” Science 323:133-138, and U.S. Pat. Nos. 7,056,676, 7,056,661, 7,052,847, and 7,033,764, the full disclosures of which are incorporated herein by reference in their entirety for all purposes. 
     In general, a polymerase enzyme is complexed with the template strand in the presence of one or more nucleotides and/or one or more nucleotide analogs. For example, in certain embodiments, labeled analogs are present representing analogous compounds to each of the four natural nucleotides, A, T, G and C, e.g., in separate polymerase reactions, as in classical Sanger sequencing, or multiplexed together, e.g., in a single reaction, as in multiplexed sequencing approaches. When a particular base in the template strand is encountered by the polymerase during the polymerization reaction, it complexes with an available analog that is complementary to such nucleotide, and incorporates that analog into the nascent and growing nucleic acid strand. In one aspect, incorporation can result in a label being released, e.g., in polyphosphate analogs, cleaving between the α and β phosphorus atoms in the analog, and consequently releasing the labeling group (or a portion thereof). The incorporation event is detected, either by virtue of a longer presence of the analog and, thus, the label, in the complex, or by virtue of release of the label group into the surrounding medium. Where different labeling groups are used for each of the types of analogs, e.g., A, T, G or C, identification of a label of an incorporated analog allows identification of that analog and consequently, determination of the complementary nucleotide in the template strand being processed at that time. Sequential reaction and monitoring permits real-time monitoring of the polymerization reaction and determination of the sequence of the template nucleic acid. As noted above, in particularly preferred aspects, the polymerase enzyme/template complex is provided immobilized within an optical confinement that permits observation of an individual complex, e.g., a zero mode waveguide. For additional information on single molecule sequencing monitoring incorporation of phosphate-labeled analogs in real time, see, e.g., Eid et al. (2009) “Real-time DNA sequencing from single polymerase molecules” Science 323:133-138. 
     In a first exemplary technique, as schematically illustrated in  FIG. 3A , a nucleic acid synthesis complex, including a polymerase enzyme  202 , a template sequence  204  and a complementary primer sequence  206 , is provided immobilized within an observation region  200  that permits illumination (as shown by hv) and observation of a small volume that includes the complex without excessive illumination of the surrounding volume (as illustrated by dashed line  208 ). By illuminating and observing only the volume immediately surrounding the complex, one can readily identify fluorescently labeled nucleotides that become incorporated during that synthesis, as such nucleotides are retained within that observation volume by the polymerase for longer periods than those nucleotides that are simply randomly diffusing into and out of that volume. 
     In particular, as shown in  FIG. 3B , when a nucleotide, e.g., A, is incorporated into DNA by the polymerase, it is retained within the observation volume for a prolonged period of time, and upon continued illumination yields a prolonged fluorescent signal (shown by peak  210 ). By comparison, randomly diffusing and not incorporated nucleotides remain within the observation volume for much shorter periods of time, and thus produce only transient signals (such as peak  212 ), many of which go undetected due to their extremely short duration. 
     In particularly preferred exemplary systems, the confined illumination volume is provided through the use of arrays of optically confined apertures termed zero mode waveguides (ZMWs), e.g., as shown by confined reaction region  200  (see, e.g., U.S. Pat. No. 6,917,726, which is incorporated herein by reference in its entirety for all purposes). For sequencing applications, the DNA polymerase is typically provided immobilized upon the bottom of the ZMW, although another component of the complex (e.g., a primer or template) is optionally immobilized on the bottom of the ZMW to localize the complex. See, e.g., Korlach et al. (2008) PNAS U.S.A. 105(4):1176-1181 and US patent application publication 2008-0032301, each of which is incorporated herein by reference in its entirety for all purposes. 
     In operation, the fluorescently labeled nucleotides (shown as A, C, G and T) bear one or more fluorescent dye groups on a terminal phosphate moiety that is cleaved from the nucleotide upon incorporation. As a result, synthesized nucleic acids do not bear the build-up of fluorescent labels, as the labeled polyphosphate groups diffuse away from the complex following incorporation of the associated nucleotide, nor do such labels interfere with the incorporation event. See, e.g., Korlach et al. (2008) Nucleosides, Nucleotides and Nucleic Acids 27:1072-1083. 
     A fluorescence time trace for a ZMW, showing pulses (peaks) representing incorporation of different nucleotide analogs, is presented in  FIG. 4 . A pulse width and interpulse distance are illustrated on the trace. The inset schematically illustrates the catalytic cycle for polymerase-mediated nucleic acid primer extension according to the exemplary reaction scheme described in US patent application publication 2012-0034602; the box indicates the portion of the catalytic cycle that corresponds to the pulse when sequencing is performed with phosphate-labeled nucleotide analogs. The remainder of the cycle corresponds to the interpulse distance. 
     In a second exemplary technique, the immobilized complex and the nucleotides to be incorporated are each provided with interactive labeling components. Upon incorporation, the nucleotide borne labeling component is brought into sufficient proximity to the complex borne (or complex proximal) labeling component, such that these components produce a characteristic signal event. For example, the polymerase may be provided with a fluorophore that provides fluorescent resonant energy transfer (FRET) to appropriate acceptor fluorophores. These acceptor fluorophores are provided upon the nucleotide to be incorporated, where each type of nucleotide bears a different acceptor fluorophore, e.g., that provides a different fluorescent signal. Upon incorporation, the donor and acceptor are brought close enough together to generate energy transfer signal. By providing different acceptor labels on the different types of nucleotides, one obtains a characteristic FRET-based fluorescent signal for the incorporation of each type of nucleotide, as the incorporation is occurring. 
     In a related aspect, a nucleotide analog may include two interacting fluorophores that operate as a donor/quencher pair, where one member is present on the nucleobase or other retained portion of the nucleotide, while the other member is present on a phosphate group or other portion of the nucleotide that is released upon incorporation, e.g., a terminal phosphate group. Prior to incorporation, the donor and quencher are sufficiently proximal on the same analog as to provide characteristic signal quenching. Upon incorporation and cleavage of the terminal phosphate groups, e.g., bearing a donor fluorophore, the quenching is removed and the resulting characteristic fluorescent signal of the donor is observable. 
     In exploiting the foregoing processes, where the incorporation reaction occurs too rapidly, it may result in the incorporation event not being detected, i.e., the event speed exceeds the detection speed of the monitoring system. The missed detection of incorporated nucleotides can lead to an increased rate of errors in sequence determination, as omissions in the real sequence. In order to mitigate the potential for missed pulses due to short reaction or product release times, in one aspect, the current invention can result in increased reaction and/or product release times during incorporation cycles. Similarly, very short interpulse distances can occasionally cause pulse merging. An advantage of employing polymerases with reduced reaction rates, e.g., polymerases exhibiting decreased rates and/or two slow-step kinetics as described in US patent application publications 2009-0286245 and 2010-0112645, is an increased frequency of longer, detectable, binding events. This advantage may also be seen as an increased ratio of longer, detectable pulses to shorter, non-detectable pulses, where the pulses represent binding events. 
     In addition to their use in sequencing, the polymerases of the invention are also useful in a variety of other genotyping analyses, e.g., SNP genotyping using single base extension methods, real time monitoring of amplification, e.g., RT-PCR methods, and the like. The polymerases of the invention are also useful in amplifying nucleic acids, e.g., DNAs or RNAs, including, for example, in applications such as whole genome amplification. For example, polymerases of the invention that show increased thermostability or resistance to organic solvents (e.g., DMSO), or that otherwise exhibit an improved ability to read through damaged, modified, or other “difficult” stretches of nucleic acid template, can be suitably employed in whole genome amplification. For review of whole genome amplification, see, e.g., Silander and Saarela (2008) “Whole Genome Amplification with Phi29 DNA Polymerase to Enable Genetic or Genomic Analysis of Samples of Low DNA Yield” Methods in Molecular Biology 439:1-18 and Pinard et al. (2006) “Assessment of whole genome amplification-induced bias through high-throughput, massively parallel whole genome sequencing” BMC Genomics 7:216. Further details regarding sequencing and nucleic acid amplification can be found, e.g., in Sambrook, Ausubel, and Innis, all infra. 
     Recombinant Polymerases with Increased Stability and Readlength 
     The compositions of the invention comprise a modified recombinant DNA polymerase which exhibits one or more altered properties desirable in single molecule sequencing applications or other applications involving nucleic acid synthesis. An exemplary property of certain polymerases of the invention is increased stability (e.g., thermostability, e.g., of a polymerase-DNA substrate binary complex) relative to a wild-type or parental polymerase. Other exemplary properties include increased readlength, enhanced utility with large nucleotide analogs, altered kinetic behavior (e.g., demonstration of slow catalytic steps), exonuclease deficiency, increased closed complex stability, altered (e.g., reduced) branching fraction, altered cofactor selectivity, increased yield, increased cosolvent resistance, increased phototolerance, increased accuracy, and increased speed. 
     As will be understood, a polymerase of the invention can display one of the aforementioned properties alone or can display two or more of the properties in combination. Moreover, it will be understood that while a polymerase or group of polymerases may be described with respect to a particular property, the polymerase(s) may possess additional modified properties not mentioned in every instance for ease of discussion. It will also be understood that particular properties are observed under certain conditions. For example, a stability-improving mutation can, e.g., confer increased stability on the polymerase-DNA substrate binary complex (as compared to such a complex containing a parental polymerase lacking the mutation) when observed in a thermal inactivation assay or it can confer increased readlength when observed in a single molecule sequencing reaction where the lifetime of the parental polymerase-DNA substrate complex (and therefore readlength) is limited by its stability. A single mutation (e.g., a single amino acid substitution, deletion, insertion, or the like) may give rise to the one or more altered properties, or the one or more properties may result from two or more mutations which act in concert to confer the desired activity. The recombinant polymerases, mutations, and altered properties exhibited by the recombinant polymerases are set forth in greater detail below. 
     As noted, various combinations of the individual mutations described herein can be introduced into recombinant polymerases to confer a variety of advantageous properties on the polymerases. However, introducing additional mutations into a polymerase can have deleterious effects on its thermostability. Without limitation to any particular mechanism, thermostability of the free polymerase (uncomplexed with DNA substrate and/or nucleotide analog) is in many cases generally correlated with yield when the polymerase is purified. Mutations that increase protein thermostability are thus desirable, not only because such mutations often also increase protein yield, but also because increased thermostability can result in longer lifetime of the polymerase, e.g., during storage, under assay conditions used in single molecule sequencing or nucleic amplification at elevated temperatures, or the like. (See, e.g., US patent application publication 2012-0034602.) 
     Protein thermostability can be assayed by any of a variety of techniques known in the art. For example, polymerase thermostability can be assessed basically as described in Vedadi et al. (2006) Proc Natl Acad Sci 103:15835-15840. Purified polymerase is incubated with the florescent dye SYPRO® orange, which binds more strongly to partially unfolded protein than to folded or unfolded protein. Fluorescence is monitored as the temperature is increased. The unfolding temperature is determined as the temperature of the midpoint between the initial minimum and maximum in florescent intensity. A recombinant polymerase with increased thermostability thus has a higher unfolding temperature, while a polymerase with decreased thermostability has a lower unfolding temperature. 
     Positions relative to a wild-type Φ29 polymerase that can be mutated to increase thermostability of the free polymerase include, e.g., Y224, V250, T368, E508, E515, and/or F526. Exemplary substitutions that can enhance polymerase stability include, e.g., Y224K, V250I, T368F, T368Y, E508R, E515Q, E515K, and F526L. 
     Thermostability can also be assessed by measuring activity after incubation of the polymerase at different temperatures, optionally in the presence of a substrate and nucleotides or nucleotide analogs. Without limitation to any particular mechanism, stability of a polymerase-DNA substrate-nucleotide ternary complex (e.g., a complex including a polymerase, a primer and template, and a nucleotide or nucleotide analog) and/or stability of a polymerase-DNA substrate binary complex (e.g., including a polymerase and a primer and template) is in many cases generally correlated with readlength, e.g., readlength observed in single molecule sequencing. 
     An exemplary thermal inactivation assay in which the stability of a ternary complex including the polymerase, a gapped duplex DNA substrate, and a cognate nucleotide or nucleotide analog is assessed is described in US patent application publication 2012-0034602. Positions relative to a wild-type D29 polymerase that can be mutated to increase thermostability of the ternary complex include, e.g., V250, L253, T368, A484, E515, and F526. Exemplary substitutions that can enhance ternary complex stability include, e.g., V250I, L253H in combination with A437G, T368V, A484E, E515Q, E515K, and F526L. It is worth noting that stability of the ternary complex can also be influenced by the identity of other components of the complex, particularly the nucleotide or analog (see US patent application publication 2012-0034602). 
     Another exemplary thermal inactivation assay is schematically illustrated in  FIG. 5A . A complex including the polymerase, a gapped duplex DNA substrate bearing a fluorophore and a quencher, and a cognate nucleotide triphosphate or nucleotide analog (e.g., dATP or a hexaphosphate or other analog thereof) is assembled in the presence of Sr ++ . Mg ++  is then added to permit incorporation of the cognate nucleotide or analog. Since the other three nucleotides are not present, a binary complex including the polymerase and the DNA substrate (extended by two bases, in the example shown in  FIG. 5A ) results. An excess of heparin is also added, such that any polymerase that dissociates from the DNA substrate binds to the heparin. Samples of the binary complex are exposed, e.g., to temperatures between 30° C. and 50° C. for 30 minutes. The remaining nucleotides (e.g., the other three dNTPs) are then added; polymerase which has remained active and bound to the substrate displaces the oligonucleotide bearing the quencher, producing a fluorescent signal. 
     Thermal inactivation profiles for a series of Φ29 recombinant polymerases are shown in  FIG. 5B . As seen in  FIG. 5B , addition of a D570E substitution to Φ29 polymerases carrying other substitutions can increase stability of the binary complex. 
     Restoring the binary stability of polymerases destabilized by the introduction of other mutations can enhance readlength. As shown in  FIG. 5C , addition of a D570E substitution to a variety of recombinant Φ29 polymerases increases both their binary stability (indicated by the binary IT50 value shown over the graph, where the IT50 is the midpoint of the observed thermal inactivation profile) and their readlength. The control polymerase includes K131E, Y148I, Y224K, E239G, V250I, L253A, E375Y, A437G, A484E, D510K, K512Y, and E515Q substitutions. The other polymerases include K131E, Y148I, Y224K, E239G, V250I, L253A, E375Y, A437G, A484E, D510K, and K512Y substitutions in addition to the substitution noted on the graph, with or without a D570E substitution. Each of the polymerases also includes a C-terminal His10 tag and biotinylation site (BtagV7). 
     Positions relative to a wild-type Φ29 polymerase that can be mutated to enhance binary stability and/or readlength include, e.g., Q99, Y148, K131, and D570. Exemplary substitutions that can enhance binary stability include, e.g., Q99I, Y148I, K131E, D570E, D570S, D570T, D570M, D570V, D570W, D570G, and D570C. Such mutations are optionally employed in combination with each other to further enhance stability; for example, the effects of D570E and Y148I on binary stability can be approximately additive. 
     Mutations that increase the thermostability of the free polymerase do not always increase binary complex and/or ternary complex stability, and vice versa; for example, mutations that increase binary complex stability do not always increase free polymerase and ternary complex stability. For example, a Y224K substitution can increase thermostability of the free polymerase but does not appear to significantly increase binary complex stability, and an F526L substitution can increase both thermostability of the free polymerase and stability of the ternary complex but does not appear to significantly increase stability of the binary complex. 
     The assays described herein (e.g., for binary complex, ternary complex, and free polymerase stability) are optionally employed in screening mutant polymerases to identify recombinant polymerases of particular interest. For example, a parental polymerase can be mutated at one or more positions, then its binary complex, ternary complex, or free polymerase stability can be assessed. One or more additional properties can be assessed for any mutant polymerase showing altered (e.g., increased) binary complex, ternary complex, or free polymerase stability, e.g., readlength and/or yield. 
     As will be appreciated, recombinant polymerases that exhibit increased stability and/or readlength can also include additional mutations (e.g., amino acid substitutions, deletions, insertions, exogenous features, e.g., at the N- and/or C-terminus, and/or the like) which confer one or more additional desirable properties as described herein or known in the art, e.g., enhanced utility with large nucleotide analogs, reduced or eliminated exonuclease activity, convenient surface immobilization, improved sensitivity to base modifications, increased closed complex stability, reduced or increased branching, selectivity for particular metal cofactors, increased yield, increased accuracy, increased speed, and/or increased phototolerance. 
     Recombinant Polymerases for Incorporation of Large Analogs 
     Detection of optical labels in an enzymatic reaction generally entails directing excitation radiation at the reaction mixture to excite a labeling group present in the mixture, which is then separately detectable. However, prolonged exposure of chemical and biochemical reactants to radiation (e.g., light) energy during the excitation and detection of optical labels can damage components of the reaction mixture, e.g., enzymes, proteins, substrates, or the like. For example, it has been observed that, in template-directed synthesis of nucleic acids from fluorescently labeled nucleotides or nucleotide analogs, sustained exposure of the DNA polymerase to excitation radiation used in the detection of the relevant label (e.g., fluorophore) reduces the enzyme&#39;s processivity and polymerase activity. Although illuminated reactions typically proceed under conditions where the reactants (e.g., enzyme molecules, etc.) are present in excess such that any adverse effects of photodamage on any single enzyme molecule in the reaction mix do not, in general, affect operation of the assay, an increasing number of analyses that entail the use of optical labels are performed with reactants at very low concentrations. For example, polymerases can be used to synthesize DNAs from fluorescently labeled nucleotide analogs in microfluidic or nanofluidic reaction vessels or channels or in optically confined reaction volumes, e.g., in a zero-mode waveguide (ZMW) or ZMW array as described above. Analysis of small, single-analyte reaction volumes is becoming increasingly important in high-throughput applications, e.g., in DNA sequencing. However, in such reactant-limited analyses, any degradation of a critical reagent such as an enzyme molecule due to photodamage can dramatically interfere with the analysis. 
     Without limitation to any particular mechanism, observation of polymerase performance in single molecule sequencing reactions using labeled nucleotide analogs has revealed that, in many instances, photodamage involves collision of the dye moiety of an analog with the polymerase followed by crosslink formation between the dye and the polymerase. One approach to increasing polymerase phototolerance thus involves reducing the frequency of such collisions. For example, as described in U.S. patent application Ser. No. 13/756,113 “Recombinant Polymerases With Increased Phototolerance,” since the nucleotide analog is negatively charged, the frequency of collisions between the polymerase and the label can be reduced by introducing negative charges to and/or removing positive charges from the surface of the polymerase that is within reach of the dye moiety. As another example, again without limitation to any particular mechanism, photodamage to the polymerase can be reduced by employing one or more nucleotide analogs designed to reduce photodamage, e.g., by increasing the effective distance the dye moiety is maintained from the surface of the polymerase or by otherwise shielding the polymerase from collision with the dye. 
     Exemplary analogs designed to reduce photodamage are described in US patent application publication 2013/0316912 of application Ser. No._13/767,619 “Polymerase Enzyme Substrates with Protein Shield” by Keith Bjornson et al. filed Feb. 14, 2013 (incorporated herein by reference in its entirety for all purposes) and include protein-shielded analogs that comprise an avidin protein (e.g., a tetrameric biotin-binding protein, avidin, streptavidin, neutravidin, tamavidin, or the like), ubiquitin, or another polypeptide moiety (e.g., a polypeptide comprising at least 60 amino acids) separating the dye and the nucleotide components of the analog (e.g., attached to and positioned between the phosphate portion of a nucleoside polyphosphate and the fluorescent dye). An exemplary protein shield analog comprises a protein, e.g., comprising at least 60 amino acids (e.g., 60 to 1,000 amino acids, e.g., 80 to 600 amino acids), a nucleotide component comprising at least one nucleoside polyphosphate attached through its phosphate portion to a first position on the protein, and a dye component comprising at least one fluorescent dye moiety attached to a second position on the protein. The first and second attachment points are spaced apart by a distance such that when a nucleoside phosphate attached to the protein component of the analog is in the active site of the polymerase enzyme, a fluorescent dye moiety attached to the protein is shielded by the protein from coming into contact with the polymerase. The analog optionally includes two or more nucleoside phosphates and/or two or more fluorescent dye moieties. Each nucleoside polyphosphate optionally includes three or more phosphate groups, e.g., 4-7 or more phosphates. The nucleotide and/or dye components can be covalently or noncovalently attached to the protein component of the analog. For example, the protein component of the analog can be a biotin-binding protein, to which biotinylated nucleoside polyphosphate and/or fluorescent dye moieties are bound. In one class of embodiments, the analog comprises an avidin protein having four subunits, each of which includes one biotin binding site; one or two nucleotide components each comprising one or more phospholinked nucleotide moieties; and one or two dye components each comprising one or more dye moieties. Each nucleotide and dye component is bound to the avidin protein through a biotin moiety attached to a binding site on the avidin protein. Preferably, at least one of the nucleotide or dye components comprises a bis-biotin moiety bound to two of the biotin binding sites on the avidin protein. Optionally, the avidin protein is streptavidin or a homolog or variant thereof. See US patent application publication 2013/0316912 of application Ser. No. 13/767,619 for additional details on and examples of protein shield analogs. 
     Additional exemplary analogs designed to reduce photodamage are described in U.S. patent application 61/862,502 “Protected Fluorescent Reagent Compounds” by Lubomir Sebo et al. filed Aug. 5, 2013 (incorporated herein by reference in its entirety for all purposes) and include shielded analogs that comprise a multivalent central core element being or comprising at least one fluorescent dye. Surrounding the core are multiple intermediate chemical groups, at least one of which comprises a shield element, and multiple terminal chemical groups, at least one of which comprises a nucleotide. The analog optionally includes 2-24 nucleotides, or even more than 24 nucleotides. Exemplary shield elements include neutral side chains (e.g., polyethylene glycol) and negative side chains (e.g., sulfonic acid). See U.S. patent application 61/862,502 for additional details on and examples of shielded analogs. Suitable analogs also include those described in U.S. Pat. No. 7,968,702 (incorporated herein by reference in its entirety for all purposes), in which the label is maintained at least 2 nm from the polymerase. 
     The analog optionally has a molecular weight (i.e., molecular mass) of at least 10,000, for example, a molecular weight of at least 20,000, at least 30,000, at least 40,000, at least 50,000, or even at least 60,000, at least 100,000, at least 200,000, or at least 300,000 Da. 
     As will be evident, such analogs are considerably larger than those typically employed in nucleic acid synthesis and sequencing, and their use can therefore be facilitated by modifying the polymerase to enhance their incorporation and/or to compensate for undesirable effects of the analogs&#39; size (e.g., altered pulse characteristics or an increased frequency of cognate extra errors in which a cognate analog binds to the template but dissociates before being incorporated, producing a spurious pulse and thus an insertion error). 
     The polymerase optionally includes one or more substitutions to enhance performance of the polymerase with such analogs, e.g., in single molecule sequencing. For example, where use of large analogs undesirably narrows pulse width, one or more substitutions that increase pulse width (e.g., P558A, P558F, A256S and/or S487A) can be included in the polymerase. Where use of large analogs undesirably increases interpulse distance, the polymerase can include one or more substitutions that decrease interpulse distance (e.g., V141K, L142K, E466K, D476H, E508R, L513K, and/or D523R). Pausing when large analogs are employed can be reduced by inclusion in the polymerase of one or more substitutions such as, e.g., Q99P, R306Q, R308L, K311E, and/or T441I. A polymerase for use with large analogs can also include one or more substitutions to improve stability as described above (e.g., binary complex stability, e.g., D570E or D570M, and/or free polymerase or ternary complex stability, e.g., F526L), accuracy (e.g., Q99Y, K536T, K536E, A134S and/or I524S, optionally in combination with F526L to compensate for undesirable effects of I524S on stability or yield), and/or alter another polymerase property as described herein (e.g., Y224K, E239G, L253A, E375Y, A437G, A437N, A484E, D510K, K512Y, E515Q, D570S, and/or T571V). Exemplary combinations of substitutions useful in polymerases employed in single molecule sequencing with large analogs are provided hereinbelow. See, e.g., the section entitled “Combining Mutations” and Tables 7-10 hereinbelow, as well as  FIG. 9 ; certain selected combinations included in Tables 3-6 and  FIG. 7  are also suitable for use with large analogs. 
     Design and Characterization of Recombinant Polymerases 
     In addition to methods of using the polymerases and other compositions herein, the present invention also includes methods of making the polymerases. (Polymerases made by the methods are also a feature of the invention, and it will be evident that, although various design strategies are detailed herein, no limitation of the resulting polymerases to any particular mechanism is thereby intended.) As described, methods of making a recombinant DNA polymerase can include structurally modeling a parental polymerase, e.g., using any available crystal structure and molecular modeling software or system. Based on the modeling, one or more amino acid residue positions in the polymerase are identified as targets for mutation. For example, one or more feature affecting stability (e.g., thermostability of the free polymerase, binary complex stability, and/or ternary complex stability), phototolerance, closed complex stability, nucleotide access to or removal from the active site (and, thereby, branching), binding of a DNA or nucleotide analog, product binding, etc. is identified. These residues can be, e.g., in the active site or a binding pocket or in a domain such as the exonuclease, TPR2 or thumb domain (or interface between domains) or proximal to such domains. The DNA polymerase is mutated to include different residues at such positions (e.g., another one of the nineteen other commonly occurring natural amino acids or a non-natural amino acid, e.g., a nonpolar and/or aliphatic residue, a polar uncharged residue, an aromatic residue, a positively charged residue, or a negatively charged residue), and then screened for an activity of interest (e.g., stability (e.g., thermostability of the free polymerase, binary complex stability, and/or ternary complex stability), readlength, sensitivity to base modification, analog incorporation, phototolerance, processivity, k off , K d , branching fraction, decreased rate constant, balanced rate constants, accuracy, speed, yield, cofactor selectivity, cosolvent resistance, etc.). It will be evident that catalytic and/or highly conserved residues are typically (but not necessarily) less preferred targets for mutation. 
     Further, as noted above, a polymerase of the invention (e.g., a Φ29-type DNA polymerase that includes E375, K512, L253, and/or A484 mutations) can be further modified to enhance the properties of the polymerase. For example, a polymerase comprising a combination of the above mutations can be mutated at one or more additional sites to enhance a property already possessed by the polymerase or to confer a new property not provided by the existing mutations. Details correlating polymerase structure with desirable functionalities that can be added to polymerases of the invention are provided herein. Also provide below are various approaches for modifying/mutating polymerases of the invention, determining kinetic parameters or other properties of the modified polymerases, screening modified polymerases, and adding exogenous features to the N- and/or C-terminal regions of the polymerases. 
     Structure-Based Design of Recombinant Polymerases 
     Structural data for a polymerase can be used to conveniently identify amino acid residues as candidates for mutagenesis to create recombinant polymerases, for example, having modified active site regions and/or modified domain interfaces to increase polymerase stability, improve complex stability, increase readlength, increase phototolerance, reduce reaction rates, reduce branching, reduce exonuclease activity, alter cofactor selectivity, improve yield, or confer other desirable properties. For example, analysis of the three-dimensional structure of a polymerase such as Φ29 can identify residues that are in the active polymerization site of the enzyme, residues that form part of the nucleotide analog binding pocket, and/or amino acids at an interface between domains. 
     The three-dimensional structures of a large number of DNA polymerases have been determined by x-ray crystallography and nuclear magnetic resonance (NMR) spectroscopy, including the structures of polymerases with bound templates, nucleotides, and/or nucleotide analogs. Many such structures are freely available for download from the Protein Data Bank, at (www(dot)rcsb(dot)org/pdb. Structures, along with domain and homology information, are also freely available for search and download from the National Center for Biotechnology Information&#39;s Molecular Modeling DataBase, at www(dot)ncbi(dot)nlm(dot)nih(dot)gov/Structure/MMDB/mmdb(dot)shtml. The structures of Φ29 polymerase, Φ29 polymerase complexed with terminal protein, and Φ29 polymerase complexed with primer-template DNA in the presence and absence of a nucleoside triphosphate are available; see Kamtekar et al. (2004) “Insights into strand displacement and processivity from the crystal structure of the protein-primed DNA polymerase of bacteriophage Φ29” Mol. Cell 16(4): 609-618), Kamtekar et al. (2006) “The phi29 DNA polymerase:protein-primer structure suggests a model for the initiation to elongation transition” EMBO J. 25(6):1335-43, and Berman et al. (2007) “Structures of phi29 DNA polymerase complexed with substrate: The mechanism of translocation in B-family polymerases” EMBO J. 26:3494-3505, respectively. The structures of additional polymerases or complexes can be modeled, for example, based on homology of the polymerases with polymerases whose structures have already been determined. Alternatively, the structure of a given polymerase (e.g., a wild-type or modified polymerase), optionally complexed with a DNA (e.g., template and/or primer) and/or nucleotide analog, or the like, can be determined. 
     Techniques for crystal structure determination are well known. See, for example, McPherson (1999)  Crystallization of Biological Macromolecules  Cold Spring Harbor Laboratory; Bergfors (1999)  Protein Crystallization  International University Line; Mullin (1993)  Crystallization  Butterwoth-Heinemann; Stout and Jensen (1989)  X - ray structure determination: a practical guide,  2 nd Edition  Wiley Publishers, New York; Ladd and Palmer (1993)  Structure determination by X - ray crystallography,  3 rd Edition  Plenum Press, NewYork; Blundell and Johnson (1976)  Protein Crystallography  Academic Press, New York; Glusker and Trueblood (1985)  Crystal structure analysis: A primer,  2 nd Ed.  Oxford University Press, NewYork;  International Tables for Crystallography, Vol. F. Crystallography of Biological Macromolecules;  McPherson (2002)  Introduction to Macromolecular Crystallography  Wiley-Liss; McRee and David (1999)  Practical Protein Crystallography, Second Edition  Academic Press; Drenth (1999)  Principles of Protein X - Ray Crystallography  (Springer Advanced Texts in Chemistry) Springer-Verlag; Fanchon and Hendrickson (1991) Chapter 15 of  Crystallographic Computing, Volume  5 IUCr/Oxford University Press; Murthy (1996) Chapter 5 of  Crystallographic Methods and Protocols  Humana Press; Dauter et al. (2000) “Novel approach to phasing proteins: derivatization by short cryo-soaking with halides” Acta Cryst.D56:232-237; Dauter (2002) “New approaches to high-throughput phasing” Curr. Opin. Structural Biol. 12:674-678; Chen et al. (1991) “Crystal structure of a bovine neurophysin-II dipeptide complex at 2.8 Å determined from the single-wavelength anomalous scattering signal of an incorporated iodine atom” Proc. Natl Acad. Sci. USA, 88:4240-4244; and Gavira et al. (2002) “Ab initio crystallographic structure determination of insulin from protein to electron density without crystal handling” Acta Cryst.D58:1147-1154. 
     In addition, a variety of programs to facilitate data collection, phase determination, model building and refinement, and the like are publicly available. Examples include, but are not limited to, the HKL2000 package (Otwinowski and Minor (1997) “Processing of X-ray Diffraction Data Collected in Oscillation Mode” Methods in Enzymology 276:307-326), the CCP4 package (Collaborative Computational Project (1994) “The CCP4 suite: programs for protein crystallography” Acta Crystallogr D 50:760-763), SOLVE and RESOLVE (Terwilliger and Berendzen (1999) Acta Crystallogr D 55 (Pt 4):849-861), SHELXS and SHELXD (Schneider and Sheldrick (2002) “Substructure solution with SHELXD” Acta Crystallogr D Biol Crystallogr 58:1772-1779), Refmac5 (Murshudov et al. (1997) “Refinement of Macromolecular Structures by the Maximum-Likelihood Method” Acta Crystallogr D 53:240-255), PRODRG (van Aalten et al. (1996) “PRODRG, a program for generating molecular topologies and unique molecular descriptors from coordinates of small molecules” J Comput Aided Mol Des 10:255-262), and Coot (Elmsley et al. (2010) “Features and Development of Coot” Acta Cryst D 66:486-501. 
     Techniques for structure determination by NMR spectroscopy are similarly well described in the literature. See, e.g., Cavanagh et al. (1995)  Protein NMR Spectroscopy: Principles and Practice,  Academic Press; Levitt (2001)  Spin Dynamics: Basics of Nuclear Magnetic Resonance,  John Wiley &amp; Sons; Evans (1995)  Biomolecular NMR Spectroscopy,  Oxford University Press; Wilthrich (1986)  NMR of Proteins and Nucleic Acids  (Baker Lecture Series), Kurt Wiley-Interscience; Neuhaus and Williamson (2000)  The Nuclear Overhauser Effect in Structural and Conformational Analysis,  2nd Edition, Wiley-VCH; Macomber (1998)  A Complete Introduction to Modern NMR Spectroscopy,  Wiley-Interscience; Downing (2004)  Protein NMR Techniques  (Methods in Molecular Biology), 2nd edition, Humana Press; Clore and Gronenborn (1994)  NMR of Proteins  (Topics in Molecular and Structural Biology), CRC Press; Reid (1997)  Protein NMR Techniques,  Humana Press; Krishna and Berliner (2003)  Protein NMR for the Millenium  (Biological Magnetic Resonance), Kluwer Academic Publishers; Kiihne and De Groot (2001)  Perspectives on Solid State NMR in Biology  (Focus on Structural Biology, 1), Kluwer Academic Publishers; Jones et al. (1993)  Spectroscopic Methods and Analyses: NMR, Mass Spectrometry, and Related Techniques  (Methods in Molecular Biology, Vol. 17), Humana Press; Goto and Kay (2000) Curr. Opin. Struct. Biol. 10:585; Gardner (1998) Annu. Rev. Biophys. Biomol. Struct. 27:357; Wilthrich (2003) Angew. Chem. Int. Ed. 42:3340; Bax (1994) Curr. Opin. Struct. Biol. 4:738; Pervushin et al. (1997) Proc. Natl. Acad. Sci. U.S.A. 94:12366; Fiaux et al. (2002) Nature 418:207; Fernandez and Wider (2003) Curr. Opin. Struct. Biol. 13:570; Ellman et al. (1992) J. Am. Chem. Soc. 114:7959; Wider (2000) BioTechniques 29:1278-1294; Pellecchia et al. (2002) Nature Rev. Drug Discov. (2002) 1:211-219; Arora and Tamm (2001) Curr. Opin. Struct. Biol. 11:540-547; Flaux et al. (2002) Nature 418:207-211; Pellecchia et al. (2001) J. Am. Chem. Soc. 123:4633-4634; and Pervushin et al. (1997) Proc. Natl. Acad. Sci. USA 94:12366-12371. 
     The structure of a polymerase or of a polymerase bound to a DNA or with a given nucleotide analog incorporated into the active site can, as noted, be directly determined, e.g., by x-ray crystallography or NMR spectroscopy, or the structure can be modeled based on the structure of the polymerase and/or a structure of a polymerase with a natural nucleotide bound. The active site or other relevant domain of the polymerase can be identified, for example, by homology with other polymerases, examination of polymerase-template or polymerase-nucleotide co-complexes, biochemical analysis of mutant polymerases, and/or the like. The position of a nucleotide analog (as opposed to an available nucleotide structure) in the active site can be modeled, for example, by projecting the location of non-natural features of the analog (e.g., additional phosphate or phosphonate groups in the phosphorus containing chain linked to the nucleotide, e.g., tetra, penta or hexa phosphate groups, detectable labeling groups, e.g., fluorescent dyes, or the like) based on the previously determined location of another nucleotide or nucleotide analog in the active site. 
     Such modeling of the nucleotide analog or template (or both) in the active site can involve simple visual inspection of a model of the polymerase, for example, using molecular graphics software such as the PyMOL viewer (open source, freely available on the World Wide Web at www(dot)pymol(dot)org), Insight II, or Discovery Studio 2.1 (commercially available from Accelrys at (www (dot) accelrys (dot) com/products/discovery-studio). Alternatively, modeling of the active site complex of the polymerase or a putative mutant polymerase, for example, can involve computer-assisted docking, molecular dynamics, free energy minimization, and/or like calculations. Such modeling techniques have been well described in the literature; see, e.g., Babine and Abdel-Meguid (eds.) (2004)  Protein Crystallography in Drug Design,  Wiley-VCH, Weinheim; Lyne (2002) “Structure-based virtual screening: An overview” Drug Discov. Today 7:1047-1055; Molecular Modeling for Beginners, at (www (dot) usm (dot) maine (dot) edu/˜rhodes/SPVTut/index (dot) html; and Methods for Protein Simulations and Drug Design at (www (dot) dddc (dot) ac (dot) cn/embo04; and references therein. Software to facilitate such modeling is widely available, for example, the CHARMm simulation package, available academically from Harvard University or commercially from Accelrys (at www (dot) accelrys (dot) com), the Discover simulation package (included in Insight II, supra), and Dynama (available at (www(dot) cs (dot) gsu (dot) edu/˜cscrwh/progs/progs (dot) html). See also an extensive list of modeling software at (www (dot) netsci (dot) org/Resources/Software/Modeling/MMMD/top (dot) html. 
     Visual inspection and/or computational analysis of a polymerase model, including optional comparison of models of the polymerase in different states, can identify relevant features of the polymerase, including, for example, residues that can be mutated to increase stability or readlength, as detailed above. 
     In another example, residues from domains that are in close proximity to one another are mutated to alter inter-domain interactions. As shown in  FIG. 6 , in Φ29, M429 is in the interface between the fingers domain and the rest of the polymerase. Without limitation to any particular mechanism, mutating M429 can modulate the movement of the fingers domain and alter the equilibrium between the binary and ternary complexes. An M429A substitution, for example, can narrow pulse width and speed the polymerase. 
     Amino acid sequence data, e.g., for members of a family of polymerases, can be used in conjunction with structural data to identify particular residues as candidates for mutagenesis. As one example, residues that differ between family members and that are close to the active site can be mutated. For example, as shown in  FIG. 1 , wild-type Φ29 has an alanine at position 256 while wild-type M2Y has a serine at the corresponding position (position 253 of M2Y, SEQ ID NO:2). Introducing an S253A substitution into M2Y, where positions are numbered with respect to SEQ ID NO:2, can increase readlength and decrease pulse width. An A256S substitution can be introduced into Φ29, where positions are numbered with respect to SEQ ID NO:1, e.g., to increase pulse width. As another example, wild-type Φ29 has a glutamic acid at position 175 while wild-type M2Y has an arginine at the corresponding position (position 172 of M2Y, SEQ ID NO:2). An E175R substitution can be introduced into Φ29, where positions are numbered with respect to SEQ ID NO:1, or an R172E substitution can be introduced into M2Y, where positions are numbered with respect to SEQ ID NO:2. As yet another example, wild-type Φ29 has a tyrosine at position 224 while wild-type M2Y has a lysine at the corresponding position (position 221 of M2Y, SEQ ID NO:2). A Y224K substitution can be introduced into Φ29, where positions are numbered with respect to SEQ ID NO:1, or a K221Y substitution can be introduced into M2Y, where positions are numbered with respect to SEQ ID NO:2. As yet another example, wild-type Φ29 has a methionine at position 506 while wild-type M2Y has a valine at the corresponding position (position 503 of M2Y, SEQ ID NO:2). A V503M substitution can be introduced into M2Y, where positions are numbered with respect to SEQ ID NO:2. As yet another example, wild-type Φ29 has an aspartic acid at position 570 and a threonine at position 571 while wild-type M2Y has a serine and a valine at the corresponding positions (positions 567 and 568 of M2Y, SEQ ID NO:2). A D570S and/or a T571V substitution can be introduced into Φ29, where positions are numbered with respect to SEQ ID NO:1, e.g., to increase processivity (particularly when D570S and T571V are employed in combination with each other). 
     Combining Mutations 
     As noted repeatedly, the various mutations described herein can be combined in recombinant polymerases of the invention. Combination of mutations can be random, or more desirably, guided by the properties of the particular mutations and the characteristics desired for the resulting polymerase. Additional mutations can also be introduced into a polymerase to compensate for deleterious effects of otherwise desirable mutations. 
     A large number of exemplary mutations and the properties they confer are described herein, and it will be evident that these mutations can be favorably combined in many different combinations. Exemplary combinations are also provided herein, e.g., in Tables 3-4 and 7-8 and  FIGS. 7-9 , and an example of strategies by which additional favorable combinations are readily derived follows. For the sake of simplicity, a few exemplary combinations using only a few exemplary mutations are discussed, but it will be evident that any of the mutations described herein can be employed in such strategies to produce polymerases with desirable properties. 
     For example, where a recombinant polymerase is desired to incorporate phosphate-labeled phosphate analogs and/or large analogs in a Mg ++ -containing single molecule sequencing reaction, one or more substitutions that enhance analog binding (e.g., E375Y, K512Y, and/or A484E) and one or more substitutions that alter metal cofactor usage (e.g., L253A, L253H, or L253S) can be incorporated. Polymerase speed can be enhanced by inclusion of substitutions such as A437G, E508K, V141K, L142K, D510K, and/or V250I. Accuracy can be enhanced by inclusion of substitutions such as Q99Y, E515Q, D235E, Y148I, A134S, K536T, and/or K536E. (A Q99Y, A134S, K536T, or K536E substitution can decrease the frequency of certain noncognate errors in which a G nucleotide or analog binds to a template G, producing a spurious pulse and thus an insertion error. Such errors can be more common when large analogs are employed.) Processivity can be increased by inclusion of substitutions such as K138Q, K138A, K138C, D570S, and/or T571V. Stability and/or yield can be increased by inclusion of substitutions such as E239G, V250I, Y224K, D570E, Y1481, K131E, and/or Q99I, producing combinations such as D570E and Y148I; Y224K, E239G, L253H, E375Y, A437G, A484E, D510K, K512Y, and E515Q; Y224K, E239G, V250I, L253H, E375Y, A437G, A484E, D510K, K512Y, and E515Q; and Y148I, Y224K, E239G, L253H, E375Y, A437G, A484E, D510K, K512Y, and E515Q. Stability can also be increased, e.g., by employing M2Y as the parental polymerase and/or including a stability-enhancing exogenous feature (e.g., a C-terminal exogenous feature, e.g., a His10 or other polyhistidine tag). 
     One or more substitutions that increase phototolerance (e.g., K131E, K131Q, and/or K135Q) can be included, providing combinations such as K131E,Y224K, E239G, L253H, E375Y, A437G, A484E, D510K, K512Y, and E515Q. Substitutions that reduce photodamage in some instances also undesirably increase interpulse distances, so a substitution that decreases interpulse distance can be added, providing combinations such as K131E and E508R, K135Q and E508R, and K131E, K135Q and E508R. 
     As described above, as another route to reducing photodamage to the polymerase, one or more nucleotide analogs designed to reduce photodamage, e.g., by increasing the effective distance the dye moiety is maintained from the surface of the polymerase or by otherwise shielding the polymerase from collision with the dye, can be employed. (See, e.g., U.S. patent application 61/599,149 and U.S. patent application Ser. No. 13/767,619 “Polymerase Enzyme Substrates with Protein Shield,” which describe protein-shielded analogs that include streptavidin, ubiquitin, or the like, U.S. patent application 61/862,502, which describes additional shielded analogs, and U.S. Pat. No. 7,968,702, which describes analogs in which the label is maintained at least 2 nm from the polymerase.) The polymerase optionally includes one or more substitutions to enhance performance of the polymerase with such analogs. For example, use of such large analogs can undesirably narrow pulse width and increase interpulse distance, so one or more substitutions that increase pulse width (e.g., P558A, P558F, A256S and/or S487A) or that decrease interpulse distance or reduce pausing (e.g., Q99P, V141K, L142K, R306Q, R308L, K311E, T441I, E466K, D476H, E508R, L513K, and/or D523R) can be included in the polymerase, providing combinations such as L142K, D570S and T571V; L142K, E508R, D570S and T571V; L142K, E508R, P558A, D570S and T571V; L142K, E508R, D523R, P558A, D570S and T571V; L142K and P558A; A256S and S487A; R306Q and R308L; V141K, L142K, A256S, R306Q, R308L, T441I, and E508R; and V141K, L142K, A256S, T441I, and E508R. 
     Exemplary polymerases for use in single molecule sequencing using large nucleotide analogs, such as the protein shield analogs described in U.S. patent application 61/599,149 and U.S. patent application Ser. No. 13/767,619 “Polymerase Enzyme Substrates with Protein Shield,” the shielded analogs described in U.S. patent application 61/862,502, or other analogs with a molecular weight of at least 10,000, can include combinations of substitutions such as, e.g., V141K, L142K, Y224K, E239G, V250I, L253A, A256S, R306Q, R308L, K311E, E375Y, A437G, T441I, A484E, S487A, E508R, D510K, K512Y, and E515Q; Y224K, E239G, V250I, L253A, A256S, E375Y, A437G, A484E, S487A, D510K, K512Y, and E515Q; V141K, L142K, Y224K, E239G, V250I, L253A, A256S, E375Y, A437G, T441I, A484E, S487A, E508R, D510K, K512Y, E515Q, and D570E; A134S, Y224K, E239G, V250I, L253A, A256S, E375Y, A437G, A484E, S487A, D510K, K512Y, and E515Q; Y224K, E239G, V250I, L253A, E375Y, A437G, A484E, E508R, D510K, K512Y, E515Q, and D570M; A134S, Y224K, E239G, V250I, L253A, E375Y, A437G, A484E, S487A, E508R, D510K, K512Y, E515Q, I524S, F526L, and D570E; L142K, Y224K, E239G, V250I, L253A, E375Y, A437G, D476H, A484E, E508R, D510K, K512Y, L513K, E515Q, and D570E; L142K, Y224K, E239G, V250I, L253A, R306Q, R308L, E375Y, A437G, D476H, A484E, E508R, D510K, K512Y, L513K, E515Q, and D570E; L142K, Y224K, E239G, V250I, L253A, R306Q, R308L, E375Y, A437G, E466K, D476H, A484E, E508R, D510K, K512Y, L513K, E515Q, and D570E; L142K, Y224K, E239G, V250I, L253A, R306Q, R308L, E375Y, A437G, E466K, D476H, A484E, E508R, D510K, K512Y, E515Q, and D570E; L142K, Y224K, E239G, V250I, L253A, E375Y, A437G, E466K, D476H, A484E, E508R, D510K, K512Y, E515Q, and D570E; L142K, Y224K, E239G, V250I, L253A, E375Y, M429A, A437G, A484E, E508R, D510K, K512Y, E515Q, and D570E; A134S, L142K, Y224K, E239G, V250I, L253A, E375Y, A437G, A484E, S487A, E508R, D510K, K512Y, E515Q, I524S, F526L, and D570E; Y224K, E239G, V250I, L253A, E375Y, A437G, A484E, S487A, E508R, D510K, K512Y, E515Q, I524S, F526L, and D570M; C106S, E239G, V250I, L253A, E375Y, A437G, A484E, E508R, D510K, K512Y, and E515Q; L142K, Y224K, D235E, E239G, V250A, L253H, E375Y, A437G, A484E, E508R, D510K, K512Y, E515Q, and D570E; Y224K, E239G, V250I, L253A, E375Y, A437G, A484E, E508R, D510K, K512Y, and E515Q; V141K, L142K, Y224K, E239G, V250I, L253A, E375Y, A437G, A484E, E508R, D510K, K512Y, and E515Q; K135Q, L142K, Y224K, E239G, V250I, L253A, R306Q, R308L, E375Y, A437G, E466K, D476H, A484E, E508R, D510R, K512Y, E515Q, D570S, and T571V; K131E, K135Q, L142K, Y224K, E239G, V250I, L253A, E375Y, A437G, A484E, E508R, D510R, K512Y, E515Q, D523R, P558A, D570S, and T571V; A49E, C106S, K114R, K131E, K135Q, L142K, Y224K, E239G, V250I, L253A, Y369E, E375Y, A437G, D476H, A484E, E508R, D510K, K512Y, E515Q, D523R, D570S, and T571V; K135Q, K138Q, L142K, Y224K, E239G, V250I, L253A, R306Q, R308L, E375Y, A437G, E466K, D476H, A484E, E508R, D510K, K512Y, E515Q, I524T, P558A, D570S, and T571V; K135Q, K138Q, L142K, Y224K, E239G, V250I, L253A, R306Q, R308L, E375Y, A437G, E466K, V475I, D476H, A484E, E508R, D510K, K512Y, E515Q, I524T, P558A, D570S, and T571V; K135Q, K138Q, L142K, Y224K, E239G, V250I, L253A, R306Q, R308L, T368S, E375Y, A437G, E466K, D476H, A484E, E508R, D510K, K512Y, E515Q, I524T, P558A, D570S, and T571V; K135Q, K138Q, L142K, Y224K, E239G, V250I, L253A, R306Q, R308L, T368S, E375Y, A437G, E466K, V475I, D476H, A484E, E508R, D510K, K512Y, E515Q, P558A, D570S, and T571V; L44A, K135Q, K138Q, L142K, Y224K, E239G, V250I, L253A, R306Q, R308L, E375Y, A437G, E466K, D476H, A484E, S487A, E508R, D510K, K512Y, E515Q, P558A, D570S, and T571V; K135Q, L142K, Y224K, E239G, V250I, L253A, R306Q, R308L, T368S, E375Y, A437G, E466K, D476H, A484E, E508R, D510R, K512Y, E515Q, P558A, D570S, and T571V; A49E, C106S, K114R, K135Q, L142K, Y224K, E239G, V250I, L253A, R306Q, R308L, E375Y, A437G, E466K, D476H, A484E, E508R, D510R, K512Y, E515Q, K536Q, K539Q, D570S, and T571V; L44A, K135Q, K138Q, L142K, Y224K, E239G, V250I, L253A, R306Q, R308L, T368S, E375Y, A437G, E466K, D476H, A484E, E508R, D510K, K512Y, E515Q, P558A, D570S, and T571V; L142K, Y224K, E239G, V250I, L253A, R306Q, R308L, E375Y, A437G, E466K, D476H, A484E, E508R, D510K, K512Y, E515Q, P558A, D570T, and T571A; K138C, L142K, Y224K, E239G, V250I, L253A, R306Q, R308L, E375Y, A437G, E466K, D476H, A484E, E508R, D510K, K512Y, E515Q, D570S, and T571V; K138Q, L142K, Y224K, E239G, V250I, L253A, R306Q, R308L, E375Y, A437G, E466K, D476H, A484E, E508R, D510K, K512Y, E515Q, D570S, and T571V; K135Q, L142K, Y224K, E239G, V250I, L253A, R306Q, R308L, E375Y, A437G, E466K, D476H, A484E, E508R, D510R, K512Y, E515Q, K539E, D570S, and T571V; K131E, K135Q, L142K, Y224K, E239G, V250I, L253A, E375Y, A437G, D476H, A484E, E508R, D510K, K512Y, E515Q, D523R, D570S, and T571V; and L142K, Y224K, E239G, V250I, L253A, R306Q, R308L, E375Y, A437G, E466K, D476H, A484E, E508R, D510K, K512Y, E515Q, and D570M. 
     Detection of base modifications (e.g., 5-methylcytosine, e.g., as described in WO 2012/065043 “Classification of Nucleic Acid Templates” and U.S. patent application 61/617,999, filed Mar. 30, 2012 and entitled “Methods and Compositions for Sequencing Modified Nucleic Acids”) can be enhanced by inclusion of substitutions such as Q99W, producing combinations such as Q99W,Y224K, E239G, L253H, E375Y, A437G, A484E, D510K, K512Y, and E515Q; Q99W, K131E, Y224K, E239G, L253H, E375Y, A437G, A484E, D510K, K512Y, and E515Q; Q99W, Y148I, Y224K, E239G, L253H, E375Y, A437G, A484E, D510K, K512Y, and E515Q; Q99W,Y224K, E239G, V250I, L253H, E375Y, A437G, A484E, D510K, K512Y, and E515Q; Q99W, K131E, Y148I, Y224K, E239G, V250I, L253H, E375Y, A437G, A484E, D510K, K512Y, and E515Q; and Q99W, K131E, Y148I, Y224K, E239G, V250I, L253A, E375Y, A437G, A484E, D510K, K512Y, and E515Q. 
     For applications involving nucleic acid amplification at elevated temperature, suitable polymerases typically include mutations that enhance stability (e.g., polymerase stability, binary complex stability, and/or ternary complex stability). Thus, a polymerase suitable for performing whole genome amplification can include, e.g., substitutions that increase binary complex stability, e.g., D570E, Y148I, and/or K131E. The polymerase can also include substitutions that increase stability and/or yield of the free polymerase, e.g., Y224K, E239G, and/or F526L, providing combinations such as K131E, Y148I, Y224K, and D570E. The polymerase can be derived from an M2Y parental polymerase to further enhance stability and/or can include a stability-enhancing exogenous feature (e.g., a C-terminal exogenous feature, e.g., a His10 or other polyhistidine tag). The polymerase can include a substitution that can enhance its ability to read through sites of DNA damage, e.g., L253A, providing combinations such as K131E, Y148I, Y224K, L253A, and D570E. A polymerase suitable for performing single molecule sequencing at higher temperature (e.g., 30° C. and above) can include such stability-enhancing features (e.g., substitutions that increase polymerase, binary complex, and/or ternary complex stability, a C-terminal tag, and/or an M2Y parental polymerase) as well as mutations that broaden pulse width to facilitate detection of nucleotide incorporation events, for example, a combination such as K131E, Y224K, E239G, V250I, L253A, A256S, E375Y, A437G, C455A, A484E, D510K, K512Y, E515Q, F526L, and D570E. 
     It will be evident that different polymerase properties, and therefore different combinations of mutations, are desirable for different applications involving recombinant polymerases. For example, for certain sequencing applications, accuracy can be emphasized. Suitable exemplary combinations of mutations for use in such polymerases include, e.g., Q99I, K131E, A134S, Y224K, E239G, V250I, L253A, E375Y, A437N, A484E, E508R, D510K, K512Y, E515Q, and D570E; Q99I, K131E, A134S, Y224K, E239G, V250I, L253A, R306Q, E375Y, A437N, A484E, E508R, D510K, K512Y, E515Q, and D570E; K131E, A134S, Y224K, E239G, V250I, L253A, E375Y, A437N, A484E, E508R, D510K, K512Y, E515Q, and D570E; K131E, A134S, Y148I, Y224K, D235E, E239G, L253H, E375Y, A437G, A484E, D510K, K512Y, and E515Q; and K131E, Y148I, E239G, V250I, L253A, E375Y, A437G, A484E, D510K, K512Y, and E515Q (optionally with an alanine at position 256). 
     In other sequencing applications such as scaffolding for genome assembly or finishing (see, e.g., Koren et al. (2012) “Hybrid error correction and de novo assembly of single-molecule sequencing reads” Nat Biotechnol. 30(7):693-700), readlength can be optimized. Exemplary combinations of substitutions suitable for such applications include, e.g., K131E, L142K, Y224K, D235E, E239G, V250A, L253H, E375Y, A437G, A484E, E508R, D510K, K512Y, and E515Q; K131E, Y224K, E239G, V250I, L253A, E375Y, A437G, C455A, A484E, D510K, K512Y, and E515Q; K131E, Y224K, E239G, L253H, E375Y, M429A, A437G, C455A, A484E, D510K, K512Y, and E515Q; C11A, C106S, K131E, Y224K, E239G, L253H, C290F, K337C, E375Y, A437G, C448V, A484E, D510K, K512Y, and E515Q; and K131E, Y148I, Y224K, E239G, V250I, L253A, E375Y, M429A, A437G, A484E, D510K, K512Y, and E515Q. 
     Many other such recombinant polymerases, including these mutations and/or those described elsewhere herein, will be readily apparent and are features of the invention. 
     Mutating Polymerases 
     Various types of mutagenesis are optionally used in the present invention, e.g., to modify polymerases to produce variants, e.g., in accordance with polymerase models and model predictions as discussed above, or using random or semi-random mutational approaches. In general, any available mutagenesis procedure can be used for making polymerase mutants. Such mutagenesis procedures optionally include selection of mutant nucleic acids and polypeptides for one or more activity of interest (e.g., enhanced performance with large nucleotide analogs (e.g., protein shield analogs), increased thermostability, increased readlength, increased sensitivity to base modifications, increased phototolerance, reduced reaction rates, decreased exonuclease activity, increased complex stability, decreased branching fraction, altered metal cofactor selectivity, improved processivity, increased yield, increased accuracy, and/or improved k off , K m , V max , k cat  etc., e.g., for a given nucleotide analog). Procedures that can be used include, but are not limited to: site-directed point mutagenesis, random point mutagenesis, in vitro or in vivo homologous recombination (DNA shuffling and combinatorial overlap PCR), mutagenesis using uracil containing templates, oligonucleotide-directed mutagenesis, phosphorothioate-modified DNA mutagenesis, mutagenesis using gapped duplex DNA, point mismatch repair, mutagenesis using repair-deficient host strains, restriction-selection and restriction-purification, deletion mutagenesis, mutagenesis by total gene synthesis, degenerate PCR, double-strand break repair, and many others known to persons of skill. The starting polymerase for mutation can be any of those noted herein, including available polymerase mutants such as those identified e.g., in WO 2007/076057 “Polymerases for Nucleotide Analogue Incorporation” by Hanzel et al.; WO 2008/051530 “Polymerase Enzymes and Reagents for Enhanced Nucleic Acid Sequencing”; US patent application publication 2010-0075332 “Engineering Polymerases and Reaction Conditions for Modified Incorporation Properties” by Pranav Patel et al.; US patent application publication 2010-0093555 “Enzymes Resistant to Photodamage” by Keith Bjornson et al.; US patent application publication 2010-0112645 “Generation of Modified Polymerases for Improved Accuracy in Single Molecule Sequencing” by Sonya Clark et al.; US patent application publication 2011-0189659 “Generation of Modified Polymerases for Improved Accuracy in Single Molecule Sequencing” by Sonya Clark et al.; US patent application publication 2012-0034602 “Recombinant Polymerases For Improved Single Molecule Sequencing”; U.S. patent application Ser. No. 13/756,113 filed Jan. 31, 2013 by Satwik Kamtekar et al. and entitled “Recombinant Polymerases with Increased Phototolerance”; Hanzel et al. WO 2007/075987 “Active Surface Coupled Polymerases”; and Hanzel et al. 2007/075873 “Protein Engineering Strategies to Optimize Activity of Surface Attached Proteins.” 
     Optionally, mutagenesis can be guided by known information from a naturally occurring polymerase molecule, or of a known altered or mutated polymerase (e.g., using an existing mutant polymerase as noted in the preceding references), e.g., sequence, sequence comparisons, physical properties, crystal structure and/or the like as discussed above. However, in another class of embodiments, modification can be essentially random (e.g., as in classical or “family” DNA shuffling, see, e.g., Crameri et al. (1998) “DNA shuffling of a family of genes from diverse species accelerates directed evolution” Nature 391:288-291). 
     Additional information on mutation formats is found in: Sambrook et al.,  Molecular Cloning—A Laboratory Manual  (3rd Ed.), Vol. 1-3, Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, 2000 (“Sambrook”);  Current Protocols in Molecular Biology,  F. M. Ausubel et al., eds., Current Protocols, a joint venture between Greene Publishing Associates, Inc. and John Wiley &amp; Sons, Inc., (supplemented through 2012) (“Ausubel”)); and  PCR Protocols A Guide to Methods and Applications  (Innis et al. eds) Academic Press Inc. San Diego, Calif. (1990) (“Innis”). The following publications and references cited within provide additional detail on mutation formats: Arnold, Protein engineering for unusual environments, Current Opinion in Biotechnology 4:450-455 (1993); Bass et al., Mutant Trp repressors with new DNA-binding specificities, Science 242:240-245 (1988); Bordo and Argos (1991) Suggestions for “Safe” Residue Substitutions in Site-directed Mutagenesis 217:721-729; Botstein &amp; Shortie, Strategies and applications of in vitro mutagenesis, Science 229:1193-1201(1985); Carter et al., Improved oligonucleotide site-directed mutagenesis using M13 vectors, Nucl. Acids Res. 13: 4431-4443 (1985); Carter, Site-directed mutagenesis, Biochem. J. 237:1-7 (1986); Carter, Improved oligonucleotide-directed mutagenesis using M13 vectors, Methods in Enzymol. 154: 382-403 (1987); Dale et al., Oligonucleotide-directed random mutagenesis using the phosphorothioate method, Methods Mol. Biol. 57:369-374 (1996); Eghtedarzadeh &amp; Henikoff, Use of oligonucleotides to generate large deletions, Nucl. Acids Res. 14: 5115 (1986); Fritz et al., Oligonucleotide-directed construction of mutations: a gapped duplex DNA procedure without enzymatic reactions in vitro, Nucl. Acids Res. 16: 6987-6999 (1988); Grundström et al., Oligonucleotide-directed mutagenesis by microscale ‘shot-gun’ gene synthesis, Nucl. Acids Res. 13: 3305-3316 (1985); Hayes (2002) Combining Computational and Experimental Screening for rapid Optimization of Protein Properties PNAS 99(25) 15926-15931; Kunkel, The efficiency of oligonucleotide directed mutagenesis, in Nucleic Acids &amp; Molecular Biology (Eckstein, F. and Lilley, D. M. J. eds., Springer Verlag, Berlin)) (1987); Kunkel, Rapid and efficient site-specific mutagenesis without phenotypic selection, Proc. Natl. Acad. Sci. USA 82:488-492 (1985); Kunkel et al., Rapid and efficient site-specific mutagenesis without phenotypic selection, Methods in Enzymol. 154, 367-382 (1987); Kramer et al., The gapped duplex DNA approach to oligonucleotide-directed mutation construction, Nucl. Acids Res. 12: 9441-9456 (1984); Kramer &amp; Fritz Oligonucleotide-directed construction of mutations via gapped duplex DNA, Methods in Enzymol. 154:350-367 (1987); Kramer et al., Point Mismatch Repair, Cell 38:879-887 (1984); Kramer et al., Improved enzymatic in vitro reactions in the gapped duplex DNA approach to oligonucleotide-directed construction of mutations, Nucl. Acids Res. 16: 7207 (1988); Ling et al., Approaches to DNA mutagenesis: an overview, Anal Biochem. 254(2): 157-178 (1997); Lorimer and Pastan Nucleic Acids Res. 23, 3067-8 (1995); Mandecki, Oligonucleotide-directed double-strand break repair in plasmids of  Escherichia coli:  a method for site-specific mutagenesis, Proc. Natl. Acad. Sci. USA, 83:7177-7181 (1986); Nakamaye &amp; Eckstein, Inhibition of restriction endonuclease Nci I cleavage by phosphorothioate groups and its application to oligonucleotide-directed mutagenesis, Nucl. Acids Res. 14: 9679-9698 (1986); Nambiar et al., Total synthesis and cloning of a gene coding for the ribonuclease S protein, Science 223: 1299-1301 (1984); Sakamar and Khorana, Total synthesis and expression of a gene for the a-subunit of bovine rod outer segment guanine nucleotide-binding protein (transducin), Nucl. Acids Res. 14: 6361-6372 (1988); Sayers et al., Y-T Exonucleases in phosphorothioate-based oligonucleotide-directed mutagenesis, Nucl. Acids Res. 16:791-802 (1988); Sayers et al., Strand specific cleavage of phosphorothioate-containing DNA by reaction with restriction endonucleases in the presence of ethidium bromide, (1988) Nucl. Acids Res. 16: 803-814; Sieber, et al., Nature Biotechnology, 19:456-460 (2001); Smith, In vitro mutagenesis, Ann. Rev. Genet. 19:423-462(1985); Methods in Enzymol. 100: 468-500 (1983); Methods in Enzymol. 154: 329-350 (1987); Stemmer, Nature 370, 389-91 (1994); Taylor et al., The use of phosphorothioate-modified DNA in restriction enzyme reactions to prepare nicked DNA, Nucl. Acids Res. 13: 8749-8764 (1985); Taylor et al., The rapid generation of oligonucleotide-directed mutations at high frequency using phosphorothioate-modified DNA, Nucl. Acids Res. 13: 8765-8787 (1985); Wells et al., Importance of hydrogen-bond formation in stabilizing the transition state of subtilisin, Phil. Trans. R. Soc. Lond. A 317: 415-423 (1986); Wells et al., Cassette mutagenesis: an efficient method for generation of multiple mutations at defined sites, Gene 34:315-323 (1985); Zoller &amp; Smith, Oligonucleotide-directed mutagenesis using M13-derived vectors: an efficient and general procedure for the production of point mutations in any DNA fragment, Nucleic Acids Res. 10:6487-6500 (1982); Zoller &amp; Smith, Oligonucleotide-directed mutagenesis of DNA fragments cloned into M13 vectors, Methods in Enzymol. 100:468-500 (1983); Zoller &amp; Smith, Oligonucleotide-directed mutagenesis: a simple method using two oligonucleotide primers and a single-stranded DNA template, Methods in Enzymol. 154:329-350 (1987); Clackson et al. (1991) “Making antibody fragments using phage display libraries” Nature 352:624-628; Gibbs et al. (2001) “Degenerate oligonucleotide gene shuffling (DOGS): a method for enhancing the frequency of recombination with family shuffling” Gene 271:13-20; and Hiraga and Arnold (2003) “General method for sequence-independent site-directed chimeragenesis: J. Mol. Biol. 330:287-296. Additional details on many of the above methods can be found in Methods in Enzymology Volume 154, which also describes useful controls for trouble-shooting problems with various mutagenesis methods. 
     Determining Kinetic Parameters 
     The polymerases of the invention can be screened or otherwise tested to determine whether the polymerase displays a modified activity for or with a nucleotide analog or template as compared to a parental DNA polymerase (e.g., a corresponding wild-type or available mutant polymerase from which the recombinant polymerase of the invention was derived). For example, branching fraction, a reaction rate constant, k off , k cat , K m , V max , k cat /K m , V max /K m , k pol , and/or K d  of the recombinant DNA polymerase for the nucleotide (or analog) or template nucleic acid can be determined. The specificity constant k cat /K m  is also a useful measure, e.g., for assessing branch rate. k cat /K m  is a measure of substrate binding that leads to product formation (and, thus, includes terms defining binding K d  and inversely predicts branching fraction formation). 
     As is well-known in the art, for enzymes obeying simple Michaelis-Menten kinetics, kinetic parameters are readily derived from rates of catalysis measured at different substrate concentrations. The Michaelis-Menten equation, V=V max [S]([S]+K m ) −1 , relates the concentration of free substrate ([S], approximated by the total substrate concentration), the maximal rate (V max , attained when the enzyme is saturated with substrate), and the Michaelis constant (K m , equal to the substrate concentration at which the reaction rate is half of its maximal value), to the reaction rate (V). 
     For many enzymes, K m  is equal to the dissociation constant of the enzyme-substrate complex and is thus a measure of the strength of the enzyme-substrate complex. For such an enzyme, in a comparison of K m s, a lower K m  represents a complex with stronger binding, while a higher Km represents a complex with weaker binding. The ratio k cat /K m , sometimes called the specificity constant, can be thought of as the second order rate constant times the probability of that substrate being converted to product once bound. The larger the specificity constant, the more efficient the enzyme is in binding the substrate and converting it to product. The specificity constant is inversely proportional to the branching rate, as branching rate is the rate at which the enzyme binds substrate (e.g., nucleotide) but does not convert it to product (e.g., a DNA polymer). 
     k cat  (also called the turnover number of the enzyme) can be determined if the total enzyme concentration ([E T ], i.e., the concentration of active sites) is known, since V max =k cat [E T ]. For situations in which the total enzyme concentration is difficult to measure, the ratio V max /K m  is often used instead as a measure of efficiency. K m  and V max  can be determined, for example, from a Lineweaver-Burk plot of 1/V against 1/[S], where the y intercept represents 1/V max , the x intercept −1/K m , and the slope K m /V max , or from an Eadie-Hofstee plot of V against V/[S], where the y intercept represents V max , the x intercept V max /K m , and the slope −K m . Software packages such as KinetAsyst™ or Enzfit (Biosoft, Cambridge, UK) can facilitate the determination of kinetic parameters from catalytic rate data. 
     For enzymes such as polymerases that have multiple substrates, varying the concentration of only one substrate while holding the others in suitable excess (e.g., effectively constant) concentration typically yields normal Michaelis-Menten kinetics. 
     Details regarding k off  determination are described, e.g., in US patent application publication 2012-0034602. In general, the dissociation rate can be measured in any manner that detects the polymerase/DNA complex over time. This includes stopped-flow spectroscopy, or even simply taking aliquots over time and testing for polymerase activity on the template of interest. Free polymerase is captured with a polymerase trap after dissociation, e.g., by incubation in the presence of heparin or an excess of competitor DNA (e.g., non-specific salmon sperm DNA, or the like). 
     In one embodiment, using pre-steady-state kinetics, the nucleotide concentration dependence of the rate constant k obs  (the observed first-order rate constant for dNTP incorporation) provides an estimate of the K m  for a ground state binding and the maximum rate of polymerization (k pol ). The k obs  is measured using a burst assay. The results of the assay are fitted with the Burst equation; Product=A[1-exp(−k obs *t)]+k ss *t where A represents amplitude an estimate of the concentration of the enzyme active sites, k ss  is the observed steady-state rate constant and t is the reaction incubation time. The K m  for dNTP binding to the polymerase-DNA complex and the k pol  are calculated by fitting the dNTP concentration dependent change in the k obs  using the equation k obs =(k pol *[S])*(K m +[S]) −1  where [S] is the substrate concentration. Results are optionally obtained from a rapid-quench experiment (also called a quench-flow measurement), for example, based on the methods described in Johnson (1986) “Rapid kinetic analysis of mechanochemical adenosinetriphosphatases” Methods Enzymol. 134:677-705, Patel et al. (1991) “Pre-steady-state kinetic analysis of processive DNA replication including complete characterization of an exonuclease-deficient mutant” Biochemistry 30(2):511-25, and Tsai and Johnson (2006) “A new paradigm for DNA polymerase specificity” Biochemistry 45(32):9675-87. 
     Parameters such as rate of binding of a nucleotide analog or template by the recombinant polymerase, rate of product release by the recombinant polymerase, or branching rate of the recombinant polymerase can also be determined, and optionally compared to that of a parental polymerase (e.g., a corresponding wild-type polymerase). 
     For a more thorough discussion of enzyme kinetics, see, e.g., Berg, Tymoczko, and Stryer (2002)  Biochemistry, Fifth Edition,  W. H. Freeman; Creighton (1984)  Proteins: Structures and Molecular Principles,  W. H. Freeman; and Fersht (1985)  Enzyme Structure and Mechanism, Second Edition,  W. H. Freeman 
     In one aspect, the improved activity of the enzymes of the invention is compared with a given parental polymerase. For example, in the case of enzymes derived from a Φ29 parental enzyme, where the improvement being sought is an increase in stability of the closed complex, an improved enzyme of the invention would have a lower k off  than the parental enzyme, e.g., wild type Φ29. Such comparisons are made under equivalent reaction conditions, e.g., equal concentrations of the parental and modified polymerase, equal substrate concentrations, equivalent solution conditions (pH, salt concentration, presence of divalent cations, etc.), temperature, and the like. In one aspect, the improved activity of the enzymes of the invention is measured with reference to a model analog or analog set and compared with a given parental enzyme. Optionally, the improved activity of the enzymes of the invention is measured under specified reaction conditions. While the foregoing may be used as a characterization tool, it in no way is intended as a specifically limiting reaction of the invention. 
     Optionally, the polymerase exhibits a K m  for a phosphate-labeled nucleotide analog that is less than a K m  observed for a wild-type polymerase for the analog to facilitate applications in which the polymerase incorporates the analog, e.g., during SMS. For example, the modified recombinant polymerase can exhibit a K m  for the phosphate-labeled nucleotide analog that is less than less than 75%, 50%, 25% or less than that of wild-type or parental polymerase such as a wild type Φ29. In one specific class of examples, the polymerases of the invention have a K m  of about 10 μM or less for a non-natural nucleotide analog such as a phosphate labeled analog. 
     Screening Polymerases 
     Screening or other protocols can be used to determine whether a polymerase displays a modified activity, e.g., for a nucleotide analog, as compared to a parental DNA polymerase. For example, branching fraction, rate constant, k off , k cat , K m , V max , or k cat /K m  of the recombinant DNA polymerase for the template or nucleotide or analog can be determined as discussed above. As another example, activity can be assayed indirectly. Assays for properties such as protein yield, thermostability, and the like are described, e.g., herein and in US patent application publication 2012-0034602. Performance of a recombinant polymerase in a sequencing reaction, e.g., a single molecule sequencing reaction, can be examined to assay properties such as speed, pulse width, interpulse distance, accuracy, readlength, ability to incorporate large nucleotide analogs, sensitivity to base modifications, etc. as described herein. Phototolerance can be assessed by monitoring polymerase performance (e.g., in a single molecule sequencing reaction) during or after exposure of the polymerase to light, e.g., excitation light of a specified wavelength at a given intensity for a given time, e.g., as compared to a wild-type or other parental polymerase. Resistance to cosolvents can be assessed by monitoring polymerase performance in the presence of varying amounts of the solvent (e.g., in a primarily aqueous solution containing various amounts of an organic solvent, e.g., DMSO, e.g., 1-10%, 2-10%, 2-5%, or 5-8% by volume of the solvent). 
     In one desirable aspect, a library of recombinant DNA polymerases can be made and screened for these properties. For example, a plurality of members of the library can be made to include one or more mutation that increases stability, increases readlength, improves detection of modified bases, enhances incorporation of large analogs, increases phototolerance, alters (e.g., decreases) reaction rate constants, improves closed complex stability, decreases branching fraction, alters cofactor selectivity, or increases cosolvent resistance, yield, accuracy, or speed, and/or randomly generated mutations (e.g., where different members include different mutations or different combinations of mutations), and the library can then be screened for the properties of interest (e.g., increased stability, readlength, utility of large analogs, or phototolerance, decreased rate constant, decreased branching fraction, increased closed complex stability, etc.). In general, the library can be screened to identify at least one member comprising a modified activity of interest. 
     Libraries of polymerases can be either physical or logical in nature. Moreover, any of a wide variety of library formats can be used. For example, polymerases can be fixed to solid surfaces in arrays of proteins. Similarly, liquid phase arrays of polymerases (e.g., in microwell plates) can be constructed for convenient high-throughput fluid manipulations of solutions comprising polymerases. Liquid, emulsion, or gel-phase libraries of cells that express recombinant polymerases can also be constructed, e.g., in microwell plates, or on agar plates. Phage display libraries of polymerases or polymerase domains (e.g., including the active site region or interdomain stability regions) can be produced. Likewise, yeast display libraries can be used. Instructions in making and using libraries can be found, e.g., in Sambrook, Ausubel and Berger, referenced herein. 
     For the generation of libraries involving fluid transfer to or from microtiter plates, a fluid handling station is optionally used. Several “off the shelf” fluid handling stations for performing such transfers are commercially available, including e.g., the Zymate systems from Caliper Life Sciences (Hopkinton, Mass.) and other stations which utilize automatic pipettors, e.g., in conjunction with the robotics for plate movement (e.g., the ORCA® robot, which is used in a variety of laboratory systems available, e.g., from Beckman Coulter, Inc. (Fullerton, Calif.). 
     In an alternate embodiment, fluid handling is performed in microchips, e.g., involving transfer of materials from microwell plates or other wells through microchannels on the chips to destination sites (microchannel regions, wells, chambers or the like). Commercially available microfluidic systems include those from Hewlett-Packard/Agilent Technologies (e.g., the HP2100 bioanalyzer) and the Caliper High Throughput Screening System. The Caliper High Throughput Screening System provides one example interface between standard microwell library formats and Labchip technologies. RainDance Technologies&#39; nanodroplet platform provides another method for handling large numbers of spatially separated reactions. Furthermore, the patent and technical literature includes many examples of microfluidic systems which can interface directly with microwell plates for fluid handling. 
     Tags and Other Optional Polymerase Features 
     The recombinant DNA polymerase optionally includes additional features exogenous or heterologous to the polymerase. For example, the recombinant polymerase optionally includes one or more tags, e.g., purification, substrate binding, or other tags, such as a polyhistidine tag, a His10 tag, a His6 tag, an alanine tag, an Ala10 tag, an Ala16 tag, a biotin tag, a biotin ligase recognition sequence or other biotin attachment site (e.g., a BiTag or a Btag or variant thereof, e.g., BtagV1-11), a GST tag, an S Tag, a SNAP-tag, an HA tag, a DSB (Sso7D) tag, a lysine tag, a NanoTag, a Cmyc tag, a tag or linker comprising the amino acids glycine and serine, a tag or linker comprising the amino acids glycine, serine, alanine and histidine, a tag or linker comprising the amino acids glycine, arginine, lysine, glutamine and proline, a plurality of polyhistidine tags, a plurality of His10 tags, a plurality of His6 tags, a plurality of alanine tags, a plurality of Ala10 tags, a plurality of Ala16 tags, a plurality of biotin tags, a plurality of GST tags, a plurality of BiTags, a plurality of S Tags, a plurality of SNAP-tags, a plurality of HA tags, a plurality of DSB (Sso7D) tags, a plurality of lysine tags, a plurality of NanoTags, a plurality of Cmyc tags, a plurality of tags or linkers comprising the amino acids glycine and serine, a plurality of tags or linkers comprising the amino acids glycine, serine, alanine and histidine, a plurality of tags or linkers comprising the amino acids glycine, arginine, lysine, glutamine and proline, biotin, avidin, an antibody or antibody domain, antibody fragment, antigen, receptor, receptor domain, receptor fragment, maltose binding protein, ligand, one or more protease site (e.g., Factor Xa, enterokinase, or thrombin site), a dye, an acceptor, a quencher, a DNA binding domain (e.g., a helix-hairpin-helix domain from topoisomerase V), a domain that binds modified bases (e.g., an MeCpG binding protein 2 domain, an O6-alkylguanine DNA alkyl transferase domain, a thymine dioxygenase JBP1 catalytic domain, or an SRA domain, e.g., from UHRF1), a sliding clamp domain or the like to increase affinity for DNA (e.g., an HSV UL42 domain), or combination thereof. See, e.g., US patent application publication 2012-0034602 for sequences of a number of suitable tags and linkers, including BtagV1-11; see also Table 11 hereinbelow. The one or more exogenous or heterologous features can find use not only for purification purposes, immobilization of the polymerase to a substrate, and the like, but can also be useful for altering one or more properties of the polymerase (e.g., addition of an exogenous feature at the C-terminus (e.g., a His10 or other polyhistidine tag) can decrease exonuclease activity and/or increase binary and/or ternary complex stability). 
     The one or more exogenous or heterologous features can be included internal to the polymerase, at the N-terminal region of the polymerase, at the C-terminal region of the polymerase, or at a combination thereof (e.g., at both the N-terminal and C-terminal regions of the polymerase). Where the polymerase includes an exogenous or heterologous feature at both the N-terminal and C-terminal regions, the exogenous or heterologous features can be the same (e.g., a polyhistidine tag, e.g., a His10 tag, at both the N- and C-terminal regions) or different (e.g., a biotin ligase recognition sequence at the N-terminal region and a polyhistidine tag, e.g., His10 tag, at the C-terminal region). Optionally, a terminal region (e.g., the N- or C-terminal region) of a polymerase of the invention can comprise two or more exogenous or heterologous features which can be the same or different (e.g., a biotin ligase recognition sequence and a polyhistidine tag at the N-terminal region, a biotin ligase recognition sequence, a polyhistidine tag, and a Factor Xa recognition site at the N-terminal region, and the like). As a few examples, the polymerase can include a polyhistidine tag at the C-terminal region, a biotin ligase recognition sequence at the N-terminal region and a polyhistidine tag at the C-terminal region, a biotin ligase recognition sequence and a polyhistidine tag at the N-terminal region, a biotin ligase recognition sequence and a polyhistidine tag at the N-terminal region and a polyhistidine tag at the C-terminal region, two biotin ligase recognition sequences at the C-terminal region (e.g., two tandem sequences, e.g., tandem Btags), or a polyhistidine tag and a biotin ligase recognition sequence at the C-terminal region. 
     For convenience, an exogenous or heterologous feature will often be expressed as a fusion domain of the overall polymerase protein, e.g., as a conventional in-frame fusion of a polypeptide sequence with the active polymerase enzyme (e.g., a polyhistidine tag fused in frame to an active polymerase enzyme sequence). However, features such as tags can be added chemically to the polymerase, e.g., by using an available amino acid residue of the enzyme or by incorporating an amino acid into the protein that provides a suitable attachment site for the coupling domain. Suitable residues of the enzyme can include, e.g., histidine, cysteine, or serine residues (providing for N, S, or O linked coupling reactions). Optionally, one or more cysteines present in the parental polymerase (e.g., up to all of the cysteines present on the polymerase&#39;s surface) can be replaced with a different amino acid; either a single reactive surface cysteine can be left unsubstituted or a single reactive surface cysteine can be introduced in place of another residue, for convenient addition of a feature, e.g., for surface immobilization through thiol labeling (e.g., addition of maleimide biotin, or maleimide and an alkyne for click labeling). Unnatural amino acids that comprise unique reactive sites can also be added to the enzyme, e.g., by expressing the enzyme in a system that comprises an orthogonal tRNA and an orthogonal synthetase that loads the unnatural amino acid in response to a selector codon. 
     The exogenous or heterologous features can find use, e.g., in the context of binding a polymerase in an active form to a surface, e.g., to orient and/or protect the polymerase active site when the polymerase is bound to a surface. In general, surface binding elements and purification tags that can be added to the polymerase (e.g., recombinantly or chemically) include, e.g., biotin attachment sites (e.g., biotin ligase recognition sequences such as Btags or BiTag), polyhistidine tags, His6 tags, His10 tags, biotin, avidin, GST sequences, modified GST sequences, e.g., that are less likely to form dimers, S tags, SNAP-tags, antibodies or antibody domains, antibody fragments, antigens, receptors, receptor domains, receptor fragments, ligands, and combinations thereof. 
     One aspect of the invention includes DNA polymerases that can be coupled to a surface without substantial loss of activity (e.g., in an active form). DNA polymerases can be coupled to the surface through a single surface coupling domain or through multiple surface coupling domains which act in concert to increase binding affinity of the polymerase for the surface and to orient the polymerase relative to the surface. For example, the active site can be oriented distal to the surface, thereby making it accessible to a polymerase substrate (template, nucleotides, etc.). This orientation also tends to reduce surface denaturation effects in the region of the active site. In a related aspect, activity of the enzyme can be protected by making the coupling domains large, thereby serving to further insulate the active site from surface binding effects. Further details regarding the immobilization of a polymerase to a surface (e.g., the surface of a zero mode waveguide) in an active form are found in WO 2007/075987 “Active Surface Coupled Polymerases” by Hanzel et al. and WO 2007/075873 “Protein Engineering Strategies to Optimize Activity of Surface Attached Proteins” by Hanzel et al. Further details on attaching tags is available in the art. See, e.g., U.S. Pat. Nos. 5,723,584 and 5,874,239 for additional information on attaching biotinylation peptides to recombinant proteins. 
     The polymerase immobilized on a surface in an active form can be coupled to the surface through one or a plurality of artificial or recombinant surface coupling domains as discussed above, and typically displays a k cat /K m  (or V max /K m ) that is at least about 1%, at least about 10%, at least about 25%, at least about 50%, or at least about 75% as high as a corresponding active polymerase in solution. 
     Exonuclease-Deficient Recombinant Polymerases 
     Many native DNA polymerases have a proof-reading exonuclease function which can yield substantial data analysis problems in processes that utilize real time observation of incorporation events as a method of identifying sequence information, e.g., single molecule sequencing applications. Even where exonuclease activity does not introduce such problems in single molecule sequencing, reduction of exonuclease activity can be desirable since it can increase accuracy (in some cases at the expense of readlength). 
     Accordingly, recombinant polymerases of the invention optionally include one or more mutations (e.g., substitutions, insertions, and/or deletions) relative to the parental polymerase that reduce or eliminate endogenous exonuclease activity. For example, relative to the wild-type Φ29 DNA polymerase of SEQ ID NO:1, one or more of positions N62, D12, E14, T15, H61, D66, D169, K143, Y148, and H149 is optionally mutated to reduce exonuclease activity. Exemplary mutations that can reduce exonuclease activity include, e.g., N62D, N62H, D12A, T15I, E14I, E14A, D66A, K143D, D145A and D169A substitutions, as well as addition of an exogenous feature at the C-terminus (e.g., a polyhistidine tag). Additional exemplary substitutions in the exonuclease domain include N62S, D12N, D12R, D12M, E14Q, H61K, H61D, H61A, D66R, D66N, D66Q, D66K, D66M, D169N, K143R, Y148K, Y148A, Y148C, Y148D, Y148E, Y148F, Y148G, Y148H, Y148I, Y148L, Y148M, Y148N, Y148P, Y148Q, Y148R, Y148S, Y148T, Y148V, Y148W, and H149M. The polymerases of the invention optionally comprise one or more of these mutations. For example, in one aspect, the polymerase is a Φ29-type polymerase that includes one or more mutations in the N-terminal exonuclease domain (residues 5-189 as numbered with respect to wild-type Φ29). 
     Making and Isolating Recombinant Polymerases 
     Generally, nucleic acids encoding a polymerase of the invention can be made by cloning, recombination, in vitro synthesis, in vitro amplification and/or other available methods. A variety of recombinant methods can be used for expressing an expression vector that encodes a polymerase of the invention. Methods for making recombinant nucleic acids, expression and isolation of expressed products are well known and described in the art. A number of exemplary mutations and combinations of mutations, as well as strategies for design of desirable mutations, are described herein. Methods for making and selecting mutations in the active site of polymerases, including for modifying steric features in or near the active site to permit improved access by nucleotide analogs are found hereinabove and, e.g., in WO 2007/076057 “Polymerases for Nucleotide Analogue Incorporation” by Hanzel et al. and WO 2008/051530 “Polymerase Enzymes and Reagents for Enhanced Nucleic Acid Sequencing” by Rank et al. 
     Additional useful references for mutation, recombinant and in vitro nucleic acid manipulation methods (including cloning, expression, PCR, and the like) include Berger and Kimmel,  Guide to Molecular Cloning Techniques, Methods in Enzymology volume  152 Academic Press, Inc., San Diego, Calif. (Berger); Kaufman et al. (2003) Handbook of Molecular and Cellular Methods in Biology and Medicine Second Edition Ceske (ed) CRC Press (Kaufman); and  The Nucleic Acid Protocols Handbook  Ralph Rapley (ed) (2000) Cold Spring Harbor, Humana Press Inc (Rapley); Chen et al. (ed)  PCR Cloning Protocols, Second Edition  (Methods in Molecular Biology, volume 192) Humana Press; and in Viljoen et al. (2005)  Molecular Diagnostic PCR Handbook  Springer, ISBN 1402034032. 
     In addition, a plethora of kits are commercially available for the purification of plasmids or other relevant nucleic acids from cells, (see, e.g., EasyPrep™, FlexiPrep™, both from Pharmacia Biotech; StrataClean™, from Stratagene; and, QIAprep™ from Qiagen). Any isolated and/or purified nucleic acid can be further manipulated to produce other nucleic acids, used to transfect cells, incorporated into related vectors to infect organisms for expression, and/or the like. Typical cloning vectors contain transcription and translation terminators, transcription and translation initiation sequences, and promoters useful for regulation of the expression of the particular target nucleic acid. The vectors optionally comprise generic expression cassettes containing at least one independent terminator sequence, sequences permitting replication of the cassette in eukaryotes, or prokaryotes, or both, (e.g., shuttle vectors) and selection markers for both prokaryotic and eukaryotic systems. Vectors are suitable for replication and integration in prokaryotes, eukaryotes, or both. 
     Other useful references, e.g. for cell isolation and culture (e.g., for subsequent nucleic acid isolation) include Freshney (1994)  Culture of Animal Cells, a Manual of Basic Technique,  third edition, Wiley-Liss, New York and the references cited therein; Payne et al. (1992)  Plant Cell and Tissue Culture in Liquid Systems  John Wiley &amp; Sons, Inc. New York, N.Y.; Gamborg and Phillips (eds) (1995)  Plant Cell, Tissue and Organ Culture;  Fundamental Methods Springer Lab Manual, Springer-Verlag (Berlin Heidelberg New York) and Atlas and Parks (eds)  The Handbook of Microbiological Media  (1993) CRC Press, Boca Raton, Fla. 
     Nucleic acids encoding the recombinant polymerases of the invention are also a feature of the invention. A particular amino acid can be encoded by multiple codons, and certain translation systems (e.g., prokaryotic or eukaryotic cells) often exhibit codon bias, e.g., different organisms often prefer one of the several synonymous codons that encode the same amino acid. As such, nucleic acids of the invention are optionally “codon optimized,” meaning that the nucleic acids are synthesized to include codons that are preferred by the particular translation system being employed to express the polymerase. For example, when it is desirable to express the polymerase in a bacterial cell (or even a particular strain of bacteria), the nucleic acid can be synthesized to include codons most frequently found in the genome of that bacterial cell, for efficient expression of the polymerase. A similar strategy can be employed when it is desirable to express the polymerase in a eukaryotic cell, e.g., the nucleic acid can include codons preferred by that eukaryotic cell. 
     A variety of protein isolation and detection methods are known and can be used to isolate polymerases, e.g., from recombinant cultures of cells expressing the recombinant polymerases of the invention. A variety of protein isolation and detection methods are well known in the art, including, e.g., those set forth in R. Scopes,  Protein Purification,  Springer-Verlag, N.Y. (1982); Deutscher,  Methods in Enzymology Vol.  182:  Guide to Protein Purification,  Academic Press, Inc. N.Y. (1990); Sandana (1997)  Bioseparation of Proteins,  Academic Press, Inc.; Bollag et al. (1996)  Protein Methods,  2 nd    Edition  Wiley-Liss, NY; Walker (1996)  The Protein Protocols Handbook  Humana Press, NJ, Harris and Angal (1990)  Protein Purification Applications: A Practical Approach  IRL Press at Oxford, Oxford, England; Harris and Angal  Protein Purification Methods: A Practical Approach  IRL Press at Oxford, Oxford, England; Scopes (1993)  Protein Purification: Principles and Practice  3 rd    Edition  Springer Verlag, NY; Janson and Ryden (1998)  Protein Purification: Principles, High Resolution Methods and Applications, Second Edition  Wiley-VCH, NY; and Walker (1998)  Protein Protocols on CD - ROM  Humana Press, NJ; and the references cited therein. Additional details regarding protein purification and detection methods can be found in Satinder Ahuj a ed.,  Handbook of Bioseparations,  Academic Press (2000). 
     Kits 
     The present invention also features kits that incorporate the polymerases of the invention, optionally with additional useful reagents such as one or more nucleotides and/or nucleotide analogs, e.g., for sequencing, nucleic acid amplification, or the like. Such kits can include the polymerase of the invention packaged in a fashion to enable use of the polymerase (e.g., the polymerase immobilized in a ZMW array), optionally with a set of different nucleotide analogs of the invention, e.g., those that are analogous to A, T, G, and C, e.g., where one or more of the analogs comprise a detectable moiety, to permit identification in the presence of the analogs (e.g., protein shield or other large analogs, e.g., analogs with a molecular weight of at least 10,000). Depending upon the desired application, the kits of the invention optionally include additional reagents, such as natural nucleotides, a control template, and other reagents, such as buffer solutions and/or salt solutions, including, e.g., divalent metal ions such as Ca ++ , Mg ++ , Mn ++  and/or Fe ++ , and standard solutions, e.g., dye standards for detector calibration. Such kits also typically include instructions for use of the compounds and other reagents in accordance with the desired application methods, e.g., nucleic acid sequencing, amplification and the like. 
     Nucleic Acid and Polypeptide Sequences and Variants 
     As described herein, the invention also features polynucleotide sequences encoding, e.g., a polymerase as described herein. Examples of polymerase sequences that include features found herein, e.g., as in Tables 3-10, are provided. However, one of skill in the art will immediately appreciate that the invention is not limited to the specifically exemplified sequences. For example, one of skill will appreciate that the invention also provides, e.g., many related sequences with the functions described herein, e.g., polynucleotides and polypeptides encoding conservative variants of a polymerase of Tables 3-10 or  FIGS. 7-9  or any other specifically listed polymerase herein. Combinations of any of the mutations noted herein or combinations of any of the mutations herein in combination with those noted in other available references relating to improved polymerases, such as Hanzel et al. WO 2007/076057 “Polymerases for Nucleotide Analogue Incorporation”; Rank et al. WO 2008/051530 “Polymerase Enzymes and Reagents for Enhanced Nucleic Acid Sequencing”; Hanzel et al. WO 2007/075987 “Active Surface Coupled Polymerases”; Hanzel et al. WO 2007/075873 “Protein Engineering Strategies to Optimize Activity of Surface Attached Proteins”; US patent application publication 2010-0075332 “Engineering Polymerases and Reaction Conditions for Modified Incorporation Properties” by Pranav Patel et al.; US patent application publication 2010-0093555 “Enzymes Resistant to Photodamage” by Keith Bjornson et al.; US patent application publication 2010-0112645 “Generation of Modified Polymerases for Improved Accuracy in Single Molecule Sequencing” by Sonya Clark et al.; US patent application publication 2011-0189659 “Generation of Modified Polymerases for Improved Accuracy in Single Molecule Sequencing” by Sonya Clark et al.; US patent application publication 2012-0034602 “Recombinant Polymerases For Improved Single Molecule Sequencing”; and U.S. patent application Ser. No. 13/756,113 filed Jan. 31, 2013 by Satwik Kamtekar et al. and entitled “Recombinant Polymerases with Increased Phototolerance” are also features of the invention. 
     Accordingly, the invention provides a variety of polypeptides (polymerases) and polynucleotides (nucleic acids that encode polymerases). Exemplary polynucleotides of the invention include, e.g., any polynucleotide that encodes a polymerase of Tables 3-10 or  FIGS. 7-9  or otherwise described herein. Because of the degeneracy of the genetic code, many polynucleotides equivalently encode a given polymerase sequence. Similarly, an artificial or recombinant nucleic acid that hybridizes to a polynucleotide indicated above under highly stringent conditions over substantially the entire length of the nucleic acid (and is other than a naturally occurring polynucleotide) is a polynucleotide of the invention. In one embodiment, a composition includes a polypeptide of the invention and an excipient (e.g., buffer, water, pharmaceutically acceptable excipient, etc.). The invention also provides an antibody or antisera specifically immunoreactive with a polypeptide of the invention (e.g., that specifically recognizes a feature of the polymerase that confers decreased branching or increased complex stability). 
     In certain embodiments, a vector (e.g., a plasmid, a cosmid, a phage, a virus, etc.) comprises a polynucleotide of the invention. In one embodiment, the vector is an expression vector. In another embodiment, the expression vector includes a promoter operably linked to one or more of the polynucleotides of the invention. In another embodiment, a cell comprises a vector that includes a polynucleotide of the invention. 
     One of skill will also appreciate that many variants of the disclosed sequences are included in the invention. For example, conservative variations of the disclosed sequences that yield a functionally similar sequence are included in the invention. Variants of the nucleic acid polynucleotide sequences, wherein the variants hybridize to at least one disclosed sequence, are considered to be included in the invention. Unique subsequences of the sequences disclosed herein, as determined by, e.g., standard sequence comparison techniques, are also included in the invention. 
     Conservative Variations 
     Owing to the degeneracy of the genetic code, “silent substitutions” (i.e., substitutions in a nucleic acid sequence which do not result in an alteration in an encoded polypeptide) are an implied feature of every nucleic acid sequence that encodes an amino acid sequence. Similarly, “conservative amino acid substitutions,” where one or a limited number of amino acids in an amino acid sequence (other than residues noted, e.g., in Tables 3-10 and  FIGS. 7-9  or elsewhere herein, as being relevant to a feature or property of interest) are substituted with different amino acids with highly similar properties, are also readily identified as being highly similar to a disclosed construct. Such conservative variations of each disclosed sequence are a feature of the present invention. 
     “Conservative variations” of a particular nucleic acid sequence refers to those nucleic acids which encode identical or essentially identical amino acid sequences, or, where the nucleic acid does not encode an amino acid sequence, to essentially identical sequences. One of skill will recognize that individual substitutions, deletions or additions which alter, add or delete a single amino acid or a small percentage of amino acids (typically less than 5%, more typically less than 4%, 2% or 1%) in an encoded sequence are “conservatively modified variations” where the alterations result in the deletion of an amino acid, addition of an amino acid, or substitution of an amino acid with a chemically similar amino acid, while retaining the relevant mutational feature (for example, the conservative substitution can be of a residue distal to the active site region, or distal to an interdomain stability region). Thus, “conservative variations” of a listed polypeptide sequence of the present invention include substitutions of a small percentage, typically less than 5%, more typically less than 2% or 1%, of the amino acids of the polypeptide sequence, with an amino acid of the same conservative substitution group. Finally, the addition of sequences which do not alter the encoded activity of a nucleic acid molecule, such as the addition of a non-functional or tagging sequence (introns in the nucleic acid, poly His or similar sequences in the encoded polypeptide, etc.), is a conservative variation of the basic nucleic acid or polypeptide. 
     Conservative substitution tables providing functionally similar amino acids are well known in the art, where one amino acid residue is substituted for another amino acid residue having similar chemical properties (e.g., aromatic side chains or positively charged side chains), and therefore does not substantially change the functional properties of the polypeptide molecule. The following sets forth example groups that contain natural amino acids of like chemical properties, where substitutions within a group is a “conservative substitution”. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Conservative amino acid substitutions 
               
            
           
           
               
               
               
               
               
            
               
                   
                   
                   
                 Positively 
                 Negatively 
               
               
                 Nonpolar and/or 
                 Polar, 
                 Aromatic 
                 Charged 
                 Charged 
               
               
                 Aliphatic Side 
                 Uncharged 
                 Side 
                 Side 
                 Side 
               
               
                 Chains 
                 Side Chains 
                 Chains 
                 Chains 
                 Chains 
               
               
                   
               
               
                 Glycine 
                 Serine 
                 Phenylalanine 
                 Lysine 
                 Aspartate 
               
               
                 Alanine 
                 Threonine 
                 Tyrosine 
                 Arginine 
                 Glutamate 
               
               
                 Valine 
                 Cysteine 
                 Tryptophan 
                 Histidine 
                   
               
               
                 Leucine 
                 Methionine 
                   
                   
                   
               
               
                 Isoleucine 
                 Asparagine 
                   
                   
                   
               
               
                 Proline 
                 Glutamine 
               
               
                   
               
            
           
         
       
     
     Nucleic Acid Hybridization 
     Comparative hybridization can be used to identify nucleic acids of the invention, including conservative variations of nucleic acids of the invention. In addition, target nucleic acids which hybridize to a nucleic acid of the invention under high, ultra-high and ultra-ultra high stringency conditions, where the nucleic acids encode mutants corresponding to those noted in Tables 3-10 and  FIGS. 7-9  or other listed polymerases, are a feature of the invention. Examples of such nucleic acids include those with one or a few silent or conservative nucleic acid substitutions as compared to a given nucleic acid sequence encoding a polymerase of Tables 3-10 and  FIGS. 7-9  (or other exemplified polymerase), where any conservative substitutions are for residues other than those noted in Tables 3-10 and  FIGS. 7-9  or elsewhere as being relevant to a feature of interest (increased stability or readlength, improved performance with large analogs, etc.). 
     A test nucleic acid is said to specifically hybridize to a probe nucleic acid when it hybridizes at least 50% as well to the probe as to the perfectly matched complementary target, i.e., with a signal to noise ratio at least half as high as hybridization of the probe to the target under conditions in which the perfectly matched probe binds to the perfectly matched complementary target with a signal to noise ratio that is at least about 5×-10× as high as that observed for hybridization to any of the unmatched target nucleic acids. 
     Nucleic acids “hybridize” when they associate, typically in solution. Nucleic acids hybridize due to a variety of well characterized physico-chemical forces, such as hydrogen bonding, solvent exclusion, base stacking and the like. An extensive guide to the hybridization of nucleic acids is found in Tijssen (1993)  Laboratory Techniques in Biochemistry and Molecular Biology—Hybridization with Nucleic Acid Probes  part I chapter 2, “Overview of principles of hybridization and the strategy of nucleic acid probe assays,” (Elsevier, New York), as well as in  Current Protocols in Molecular Biology,  Ausubel et al., eds.,  Current Protocols,  a joint venture between Greene Publishing Associates, Inc. and John Wiley &amp; Sons, Inc., (supplemented through 2012); Hames and Higgins (1995)  Gene Probes  1 IRL Press at Oxford University Press, Oxford, England, (Hames and Higgins 1) and Hames and Higgins (1995)  Gene Probes  2 IRL Press at Oxford University Press, Oxford, England (Hames and Higgins 2) provide details on the synthesis, labeling, detection and quantification of DNA and RNA, including oligonucleotides. 
     An example of stringent hybridization conditions for hybridization of complementary nucleic acids which have more than 100 complementary residues on a filter in a Southern or northern blot is 50% formalin with 1 mg of heparin at 42° C., with the hybridization being carried out overnight. An example of stringent wash conditions is a 0.2×SSC wash at 65° C. for 15 minutes (see, Sambrook, supra for a description of SSC buffer). Often the high stringency wash is preceded by a low stringency wash to remove background probe signal. An example low stringency wash is 2×SSC at 40° C. for 15 minutes. In general, a signal to noise ratio of 5× (or higher) than that observed for an unrelated probe in the particular hybridization assay indicates detection of a specific hybridization. 
     “Stringent hybridization wash conditions” in the context of nucleic acid hybridization experiments such as Southern and northern hybridizations are sequence dependent, and are different under different environmental parameters. An extensive guide to the hybridization of nucleic acids is found in Tijssen (1993), supra. and in Hames and Higgins, 1 and 2. Stringent hybridization and wash conditions can easily be determined empirically for any test nucleic acid. For example, in determining stringent hybridization and wash conditions, the hybridization and wash conditions are gradually increased (e.g., by increasing temperature, decreasing salt concentration, increasing detergent concentration and/or increasing the concentration of organic solvents such as formalin in the hybridization or wash), until a selected set of criteria are met. For example, in highly stringent hybridization and wash conditions, the hybridization and wash conditions are gradually increased until a probe binds to a perfectly matched complementary target with a signal to noise ratio that is at least 5× as high as that observed for hybridization of the probe to an unmatched target. 
     “Very stringent” conditions are selected to be equal to the thermal melting point (T m ) for a particular probe. The T m  is the temperature (under defined ionic strength and pH) at which 50% of the test sequence hybridizes to a perfectly matched probe. For the purposes of the present invention, generally, “highly stringent” hybridization and wash conditions are selected to be about 5° C. lower than the T m  for the specific sequence at a defined ionic strength and pH. 
     “Ultra high-stringency” hybridization and wash conditions are those in which the stringency of hybridization and wash conditions are increased until the signal to noise ratio for binding of the probe to the perfectly matched complementary target nucleic acid is at least 10× as high as that observed for hybridization to any of the unmatched target nucleic acids. A target nucleic acid which hybridizes to a probe under such conditions, with a signal to noise ratio of at least 1/2 that of the perfectly matched complementary target nucleic acid is said to bind to the probe under ultra-high stringency conditions. 
     Similarly, even higher levels of stringency can be determined by gradually increasing the hybridization and/or wash conditions of the relevant hybridization assay. For example, those in which the stringency of hybridization and wash conditions are increased until the signal to noise ratio for binding of the probe to the perfectly matched complementary target nucleic acid is at least 10×, 20×, 50×, 100×, or 500× or more as high as that observed for hybridization to any of the unmatched target nucleic acids. A target nucleic acid which hybridizes to a probe under such conditions, with a signal to noise ratio of at least 1/2 that of the perfectly matched complementary target nucleic acid is said to bind to the probe under ultra-ultra-high stringency conditions. 
     Nucleic acids that do not hybridize to each other under stringent conditions are still substantially identical if the polypeptides which they encode are substantially identical. This occurs, e.g., when a copy of a nucleic acid is created using the maximum codon degeneracy permitted by the genetic code. 
     Unique Subsequences 
     In some aspects, the invention provides a nucleic acid that comprises a unique subsequence in a nucleic acid that encodes a polymerase of Tables 3-10 and  FIGS. 7-9  or others described herein. The unique subsequence may be unique as compared to a nucleic acid corresponding to, e.g., a wild type Φ29-type polymerase. Alignment can be performed using, e.g., BLAST set to default parameters. Any unique subsequence is useful, e.g., as a probe to identify the nucleic acids of the invention. 
     Similarly, the invention includes a polypeptide which comprises a unique subsequence in a polymerase of Tables 3-10 and  FIGS. 7-9  or otherwise detailed herein. Here, the unique subsequence is unique as compared to, e.g., a wild type Φ29-type polymerase or previously characterized mutation thereof. 
     The invention also provides for target nucleic acids which hybridize under stringent conditions to a unique coding oligonucleotide which encodes a unique subsequence in a polypeptide selected from the modified polymerase sequences of the invention, wherein the unique subsequence is unique as compared to a polypeptide corresponding to a wild type Φ29-type polymerase. Unique sequences are determined as noted above. 
     Sequence Comparison, Identity, and Homology 
     The terms “identical” or “percent identity,” in the context of two or more nucleic acid or polypeptide sequences, refer to two or more sequences or subsequences that are the same or have a specified percentage of amino acid residues or nucleotides that are the same, when compared and aligned for maximum correspondence, as measured using one of the sequence comparison algorithms described below (or other algorithms available to persons of skill) or by visual inspection. 
     The phrase “substantially identical,” in the context of two nucleic acids or polypeptides (e.g., DNAs encoding a polymerase, or the amino acid sequence of a polymerase) refers to two or more sequences or subsequences that have at least about 60%, about 80%, about 90%, about 95%, about 98%, about 99% or more nucleotide or amino acid residue identity, when compared and aligned for maximum correspondence, as measured using a sequence comparison algorithm or by visual inspection. Such “substantially identical” sequences are typically considered to be “homologous,” without reference to actual ancestry. Preferably, the “substantial identity” exists over a region of the sequences that is at least about 50 residues in length, more preferably over a region of at least about 100 residues, and most preferably, the sequences are substantially identical over at least about 150 residues, or over the full length of the two sequences to be compared. 
     Proteins and/or protein sequences are “homologous” when they are derived, naturally or artificially, from a common ancestral protein or protein sequence. Similarly, nucleic acids and/or nucleic acid sequences are homologous when they are derived, naturally or artificially, from a common ancestral nucleic acid or nucleic acid sequence. Homology is generally inferred from sequence similarity between two or more nucleic acids or proteins (or sequences thereof). The precise percentage of similarity between sequences that is useful in establishing homology varies with the nucleic acid and protein at issue, but as little as 25% sequence similarity over 50, 100, 150 or more residues is routinely used to establish homology. Higher levels of sequence similarity, e.g., 30%, 40%, 50%, 60%, 70%, 75%, 80%, 90%, 95%, 97%, 98%, or 99% or more identity, can also be used to establish homology. Methods for determining sequence similarity percentages (e.g., BLASTP and BLASTN using default parameters) are described herein and are generally available. 
     For sequence comparison and homology determination, typically one sequence acts as a reference sequence to which test sequences are compared. When using a sequence comparison algorithm, test and reference sequences are input into a computer, subsequence coordinates are designated, if necessary, and sequence algorithm program parameters are designated. The sequence comparison algorithm then calculates the percent sequence identity for the test sequence(s) relative to the reference sequence, based on the designated program parameters. 
     Optimal alignment of sequences for comparison can be conducted, e.g., by the local homology algorithm of Smith &amp; Waterman, Adv. Appl. Math. 2:482 (1981), by the homology alignment algorithm of Needleman &amp; Wunsch, J. Mol. Biol. 48:443 (1970), by the search for similarity method of Pearson &amp; Lipman, Proc. Nat&#39;l. Acad. Sci. USA 85:2444 (1988), by computerized implementations of these algorithms (GAP, BESTFIT, FASTA, and TFASTA in the Wisconsin Genetics Software Package, Genetics Computer Group, 575 Science Dr., Madison, Wis.), or by visual inspection (see generally  Current Protocols in Molecular Biology,  Ausubel et al., eds.,  Current Protocols,  a joint venture between Greene Publishing Associates, Inc. and John Wiley &amp; Sons, Inc., supplemented through 2012). 
     One example of an algorithm that is suitable for determining percent sequence identity and sequence similarity is the BLAST algorithm, which is described in Altschul et al., J. Mol. Biol. 215:403-410 (1990). Software for performing BLAST analyses is publicly available through the National Center for Biotechnology Information. This algorithm involves first identifying high scoring sequence pairs (HSPs) by identifying short words of length W in the query sequence, which either match or satisfy some positive-valued threshold score T when aligned with a word of the same length in a database sequence. T is referred to as the neighborhood word score threshold (Altschul et al., supra). These initial neighborhood word hits act as seeds for initiating searches to find longer HSPs containing them. The word hits are then extended in both directions along each sequence for as far as the cumulative alignment score can be increased. Cumulative scores are calculated using, for nucleotide sequences, the parameters M (reward score for a pair of matching residues; always&gt;0) and N (penalty score for mismatching residues; always&lt;0). For amino acid sequences, a scoring matrix is used to calculate the cumulative score. Extension of the word hits in each direction are halted when: the cumulative alignment score falls off by the quantity X from its maximum achieved value; the cumulative score goes to zero or below, due to the accumulation of one or more negative-scoring residue alignments; or the end of either sequence is reached. The BLAST algorithm parameters W, T, and X determine the sensitivity and speed of the alignment. The BLASTN program (for nucleotide sequences) uses as defaults a wordlength (W) of 11, an expectation (E) of 10, a cutoff of 100, M=5, N=−4, and a comparison of both strands. For amino acid sequences, the BLASTP program uses as defaults a wordlength (W) of 3, an expectation (E) of 10, and the BLOSUM62 scoring matrix (see Henikoff &amp; Henikoff (1989) Proc. Natl. Acad. Sci. USA 89:10915). 
     In addition to calculating percent sequence identity, the BLAST algorithm also performs a statistical analysis of the similarity between two sequences (see, e.g., Karlin &amp; Altschul (1993) Proc. Nat&#39;l. Acad. Sci. USA 90:5873-5787). One measure of similarity provided by the BLAST algorithm is the smallest sum probability (P(N)), which provides an indication of the probability by which a match between two nucleotide or amino acid sequences would occur by chance. For example, a nucleic acid is considered similar to a reference sequence if the smallest sum probability in a comparison of the test nucleic acid to the reference nucleic acid is less than about 0.1, more preferably less than about 0.01, and most preferably less than about 0.001. 
     For reference, the amino acid sequence of a wild-type Φ29 polymerase is presented in Table 2, along with the sequences of several other wild-type Φ29-type polymerases. 
     
       
         
           
               
             
               
                 TABLE 2 
               
               
                   
               
               
                 Amino acid sequence of exemplary wild-type Φ29-type 
               
               
                 polymerases. 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
            
               
                 Φ29 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIEDHSEYKIG 
               
               
                 SEQ ID NO: 1 
                 NSLDEFMAWVLKVQADLYFHNLKFDGAFIINWLERNGFKWS 
               
               
                   
                 ADGLPNTYNTIISRMGQWYMIDICLGYKGKRKIHTVIYDSLKK 
               
               
                   
                 LPFPVKKIAKDFKLTVLKGDIDYHKERPVGYKITPEEYAYIKND 
               
               
                   
                 IQIIAEALLIQFKQGLDRMTAGSDSLKGFKDIITTKKFKKVFPTL 
               
               
                   
                 SLGLDKEVRYAYRGGFTWLNDRFKEKEIGEGMVFDVNSLYPA 
               
               
                   
                 QMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEFELKEGYIP 
               
               
                   
                 TIQIKRSRFYKGNEYLKSSGGEIADLWLSNVDLELMKEHYDLY 
               
               
                   
                 NVEYISGLKFKATTGLFKDFIDKWTYIKTTSEGAIKQLAKLML 
               
               
                   
                 NSLYGKFASNPDVTGKVPYLKENGALGFRLGEEETKDPVYTP 
               
               
                   
                 MGVFITAWARYTTITAAQACYDRIIYCDTDSIHLTGTEIPDVIK 
               
               
                   
                 DIVDPKKLGYWAHESTFKRAKYLRQKTYIQDIYMKEVDGKLV 
               
               
                   
                 EGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKVGFSRKMKPK 
               
               
                   
                 PVQVPGGVVLVDDTFTIK 
               
               
                   
               
               
                 M2Y 
                 MSRKMFSCDFETTTKLDDCRVWAYGYMEIGNLDNYKIGNSLD 
               
               
                 SEQ ID NO: 2 
                 EFMQWVMEIQADLYFHNLKFDGAFIVNWLEQHGFKWSNEGL 
               
               
                   
                 PNTYNTIISKMGQWYMIDICFGYKGKRKLHTVIYDSLKKLPFP 
               
               
                   
                 VKKIAKDFQLPLLKGDIDYHTERPVGHEITPEEYEYIKNDIEIIA 
               
               
                   
                 RALDIQFKQGLDRMTAGSDSLKGFKDILSTKKFNKVFPKLSLP 
               
               
                   
                 MDKEIRKAYRGGFTWLNDKYKEKEIGEGMVFDVNSLYPSQM 
               
               
                   
                 YSRPLPYGAPIVFQGKYEKDEQYPLYIQRIRFEFELKEGYIPTIQI 
               
               
                   
                 KKNPFFKGNEYLKNSGVEPVELYLTNVDLELIQEHYELYNVEY 
               
               
                   
                 IDGFKFREKTGLFKDFIDKWTYVKTHEEGAKKQLAKLMLNSL 
               
               
                   
                 YGKFASNPDVTGKVPYLKDDGSLGFRVGDEEYKDPVYTPMG 
               
               
                   
                 VFITAWARFTTITAAQACYDRIIYCDTDSIHLTGTEVPEIIKDIVD 
               
               
                   
                 PKKLGYWAHESTFKRAKYLRQKTYIQDIYVKEVDGKLKECSP 
               
               
                   
                 DEATTTKFSVKCAGMTDTIKKKVTFDNFAVGFSSMGKPKPVQ 
               
               
                   
                 VNGGVVLVDSVFTIK 
               
               
                   
               
               
                 B103 
                 MPRKMFSCDFETTTKLDDCRVWAYGYMEIGNLDNYKIGNSLD 
               
               
                 SEQ ID NO: 3 
                 EFMQWVMEIQADLYFHNLKFDGAFIVNWLEHHGFKWSNEGL 
               
               
                   
                 PNTYNTIISKMGQWYMIDICFGYKGKRKLHTVIYDSLKKLPFP 
               
               
                   
                 VKKIAKDFQLPLLKGDIDYHAERPVGHEITPEEYEYIKNDIEIIA 
               
               
                   
                 RALDIQFKQGLDRMTAGSDSLKGFKDILSTKKFNKVFPKLSLP 
               
               
                   
                 MDKEIRRAYRGGFTWLNDKYKEKEIGEGMVFDVNSLYPSQM 
               
               
                   
                 YSRPLPYGAPIVFQGKYEKDEQYPLYIQRIRFEFELKEGYIPTIQI 
               
               
                   
                 KKNPFFKGNEYLKNSGAEPVELYLTNVDLELIQEHYEMYNVE 
               
               
                   
                 YIDGFKFREKTGLFKEFIDKWTYVKTHEKGAKKQLAKLMFDS 
               
               
                   
                 LYGKFASNPDVTGKVPYLKEDGSLGFRVGDEEYKDPVYTPMG 
               
               
                   
                 VFITAWARFTTITAAQACYDRIIYCDTDSIHLTGTEVPEIIKDIVD 
               
               
                   
                 PKKLGYWAHESTFKRAKYLRQKTYIQDIYAKEVDGKLIECSPD 
               
               
                   
                 EATTTKFSVKCAGMTDTIKKKVTFDNFRVGFSSTGKPKPVQVN 
               
               
                   
                 GGVVLVDSVFTIK 
               
               
                   
               
               
                 GA-1 
                 MARSVYVCDFETTTDPEDCRLWAWGWMDIYNTDKWSYGEDI 
               
               
                 SEQ ID NO: 4 
                 DSFMEWALNSNSDIYFHNLKFDGSFILPWWLRNGYVHTEEDR 
               
               
                   
                 TNTPKEFTTTISGMGQWYAVDVCINTRGKNKNHVVFYDSLKK 
               
               
                   
                 LPFKVEQIAKGFGLPVLKGDIDYKKYRPVGYVMDDNEIEYLK 
               
               
                   
                 HDLLIVALALRSMFDNDFTSMTVGSDALNTYKEMLGVKQWE 
               
               
                   
                 KYFPVLSLKVNSEIRKAYKGGFTWVNPKYQGETVYGGMVFD 
               
               
                   
                 VNSMYPAMMKNKLLPYGEPVMFKGEYKKNVEYPLYIQQVRC 
               
               
                   
                 FFELKKDKIPCIQIKGNARFGQNEYLSTSGDEYVDLYVTNVDW 
               
               
                   
                 ELIKKHYDIFEEEFIGGFMFKGFIGFFDEYIDRFMEIKNSPDSSAE 
               
               
                   
                 QSLQAKLMLNSLYGKFATNPDITGKVPYLDENGVLKFRKGEL 
               
               
                   
                 KERDPVYTPMGCFITAYARENILSNAQKLYPRFIYADTDSIHVE 
               
               
                   
                 GLGEVDAIKDVIDPKKLGYWDHEATFQRARYVRQKTYFIETT 
               
               
                   
                 WKENDKGKLVVCEPQDATKVKPKIACAGMSDAIKERIRFNEF 
               
               
                   
                 KIGYSTHGSLKPKNVLGGVVLMDYPFAIK 
               
               
                   
               
               
                 AV-1 
                 MVRQSTIASPARGGVRRSHKKVPSFCADFETTTDEDDCRVWS 
               
               
                 SEQ ID NO: 5 
                 WGIIQVGKLQNYVDGISLDGFMSHISERASHIYFHNLAFDGTFI 
               
               
                   
                 LDWLLKHGYRWTKENPGVKEFTSLISRMGKYYSITVVFETGFR 
               
               
                   
                 VEFRDSFKKLPMSVSAIAKAFNLHDQKLEIDYEKPRPIGYIPTE 
               
               
                   
                 QEKRYQRNDVAIVAQALEVQFAEKMTKLTAGSDSLATYKKM 
               
               
                   
                 TGKLFIRRFPILSPEIDTEIRKAYRGGFTYADPRYAKKLNGKGS 
               
               
                   
                 VYDVNSLYPSVMRTALLPYGEPIYSEGAPRTNRPLYIASITFTA 
               
               
                   
                 KLKPNHIPCIQIKKNLSFNPTQYLEEVKEPTTVVATNIDIELWK 
               
               
                   
                 KHYDFKIYSWNGTFEFRGSHGFFDTYVDHFMEIKKNSTGGLR 
               
               
                   
                 QIAKLHLNSLYGKFATNPDITGKHPTLKDNRVSLVMNEPETRD 
               
               
                   
                 PVYTPMGVFITAYARKKTISAAQDNYETFAYADTDSLHLIGPT 
               
               
                   
                 TPPDSLWVDPVELGAWKHESSFTKSVYIRAKQYAEEIGGKLDV 
               
               
                   
                 HIAGMPRNVAATLTLEDMLHGGTWNGKLIPVRVPGGTVLKDT 
               
               
                   
                 TFTLKID 
               
               
                   
               
               
                 CP-1 
                 MTCYYAGDFETTTNEEETEVWLSCFAKVIDYDKLDTFKVNTS 
               
               
                 SEQ ID NO: 6 
                 LEDFLKSLYLDLDKTYTETGEDEFIIFFHNLKDGSFLLSFFLNN 
               
               
                   
                 DIECTYFINDMGVWYSITLEFPDFTLTFRDSLKILNFSIATMAGL 
               
               
                   
                 FKMPIAKGTTPLLKHKPEVIKPEWIDYIHVDVAILARGIFAMYY 
               
               
                   
                 EENFTKYTSASEALTEFKRIFRKSKRKFRDFFPILDEKVDDFCR 
               
               
                   
                 KHIVGAGRLPTLKHRGRTLNQLIDIYDINSMYPATMLQNALPIG 
               
               
                   
                 IPKRYKGKPKEIKEDHYYIYHIKADFDLKRGYLPTIQIKKKLDA 
               
               
                   
                 LRIGVRTSDYVTTSKNEVIDLYLTNFDLDLFLKHYDATIMYVE 
               
               
                   
                 TLEFQTESDLFDDYITTYRYKKENAQSPAEKQKAKIMLNSLYG 
               
               
                   
                 KFGAKIISVKKLAYLDDKGILRFKNDDEEEVQPVYAPVALFVT 
               
               
                   
                 SIARHFIISNAQENYDNFLYADTDSLHLFHSDSLVLDIDPSEFGK 
               
               
                   
                 WAHEGRAVKAKYLRSKLYIEELIQEDGTTHLDVKGAGMTPEI 
               
               
                   
                 KEKITFENFVIGATFEGKRASKQIKGGTLIYETTFKIRETDYLV 
               
               
                   
               
            
           
         
       
     
     Exemplary Mutation Combinations 
     A list of exemplary polymerase mutation combinations, and optional corresponding exogenous or heterologous features at the C-terminal region of the polymerase, is provided in Tables 3 and 4. Positions of amino acid substitutions are identified relative to a wild-type Φ29 DNA polymerase (SEQ ID NO:1) for the recombinant polymerases in Table 3 and relative to a wild-type M2Y DNA polymerase (SEQ ID NO:2) for the recombinant polymerases in Table 4. Polymerases of the invention (including those provided in Tables 3 and 4) can include any exogenous or heterologous feature (or combination of such features), e.g., at the N- and/or C-terminal region. For example, it will be understood that polymerase mutants in Tables 3 and 4 that do not include, e.g., a C-terminal biotinylation site can be modified to include a biotinylation site at the C-terminal region, alone or in combination with any of the exogenous or heterologous features described herein. Similarly, some or all of the exogenous features listed in Tables 3 and 4 can be omitted, or substituted or combined with any of the other exogenous features described herein, and still result in a polymerase of the invention. As will be appreciated, the numbering of amino acid residues is with respect to a particular reference polymerase, such as the wild-type sequence of the Φ29 polymerase (SEQ ID NO:1) or M2Y polymerase (SEQ ID NO:2); actual position of a mutation within a molecule of the invention may vary based upon the nature of the various modifications that the enzyme includes relative to the wild type Φ29 enzyme, e.g., deletions and/or additions to the molecule, either at the termini or within the molecule itself. 
     
       
         
           
               
             
               
                 TABLE 3 
               
             
            
               
                   
               
               
                 Exemplary mutations introduced into a Φ29 DNA polymerase. 
               
               
                 Positions are identified relative to SEQ ID NO: l. 
               
            
           
           
               
               
            
               
                   
                 C-terminal region 
               
               
                 Mutations 
                 feature(s) 
               
               
                   
               
               
                 K131E L142K Y224K D235E E239G V250A L253H 
                 His10 
               
               
                 E375Y A437G A484E E508R D510K K512Y E515Q 
                 GGGSGGGSGGGS 
               
               
                   
                 BtagV7 
               
               
                   
               
               
                 K131E Y224K E239G V2501 L253A E375Y A437G 
                 His10 
               
               
                 C455A A484E D510K K512Y E515Q 
                 GGGSGGGSGGGS 
               
               
                   
                 BtagV7 
               
               
                   
               
               
                 C11A C106S K131E Y224K E239G L253H C290F 
                 His10 
               
               
                 K337C E375Y A437G C448V A484E D510K K512Y 
                 GGGSGGGSGGGS 
               
               
                 E515Q 
                 BtagV7 
               
               
                   
               
               
                 K131E A134S Y148I Y224K D235E E239G L253H 
                 His10 
               
               
                 E375Y A437G A484E D510K K512Y E515Q 
                 GGGSGGGSGGGS 
               
               
                   
                 BtagV7 
               
               
                   
               
               
                 K131E Y148I Y224K E239G V250I L253A E375Y 
                 His10 
               
               
                 A437G A484E D510K K512Y E515Q D570E 
                 GGGSGGGSGGGS 
               
               
                   
                 BtagV7 
               
               
                   
               
               
                 Q99W K131E Y148I Y224K E239G V250I L253A 
                 His10 
               
               
                 E375Y A437G A484E D510K K512Y E515Q 
                 GGGSGGGSGGGS 
               
               
                   
                 BtagV7 
               
               
                   
               
               
                 K131E Y224K E239G V250I L253A A256S E375Y 
                 His10 
               
               
                 A437G C455A A484E D510K K512Y E515Q F526L 
                 GGGSGGGSGGGS 
               
               
                 D570E 
                 BtagV7 
               
               
                   
               
               
                 Q99I K131E A134S Y224K E239G V250I L253A 
                 His10 
               
               
                 E375Y A437N A484E E508R D510K K512Y E515Q 
                 GGGSGGGSGGGS 
               
               
                 D570E 
                 BtagV7 
               
               
                   
               
               
                 Q99I K131E A134S Y224K E239G V250I L253A 
                 His10 
               
               
                 R306Q E375Y A437N A484E E508R D510K K512Y 
                 GGGSGGGSGGGS 
               
               
                 E515Q D570E 
                 BtagV7 
               
               
                   
               
               
                 K131E Y224K E239G L253H E375Y M429A A437G 
                 His10 
               
               
                 C455A A484E D510K K512Y E515Q 
                 GGGSGGGSGGGS 
               
               
                   
                 BtagV7 
               
               
                   
               
               
                 K131E Y148I Y224K E239G V250I L253A E375Y 
                 His10 
               
               
                 A437G A484E D510K K512Y E515Q 
                 GGGSGGGSGGGS 
               
               
                   
               
               
                 K131E A134S Y224K E239G V250I L253A E375Y 
                 His10 
               
               
                 A437N A484E E508R D510K K512Y E515Q D570E 
                 GGGSGGGSGGGS 
               
               
                   
                 BtagV7 
               
               
                   
               
               
                 K131E Y148I Y224K E239G V250I L253A E375Y 
                 His10 
               
               
                 A437G A484E H485Q D510K K512Y E515Q 
                 GGGSGGGSGGGS 
               
               
                   
                 BtagV7 
               
               
                   
               
               
                 K131E Y148I Y224K E239G V250I L253A E375Y 
                 His10 
               
               
                 M429A A437G A484E D510K K512Y E515Q 
                 GGGSGGGSGGGS 
               
               
                   
                 BtagV7 
               
               
                   
               
               
                 V141K L142K Y224K E239G V250I L253A A256S 
                 His10 
               
               
                 R306Q R308L K311E E375Y A437G T441I A484E 
                 GGGSGGGSGGGS 
               
               
                 S487A E508R D510K K512Y E515Q 
                 BtagV7 
               
               
                   
               
               
                 Y224K E239G V250I L253A A256S E375Y A437G 
                 His10 
               
               
                 A484E S487A D510K K512Y E515Q 
                 GGGSGGGSGGGS 
               
               
                   
                 BtagV7 
               
               
                   
               
               
                 V141K L142K Y224K E239G V250I L253A A256S 
                 His10 
               
               
                 E375Y A437G T441I A484E S487A E508R D510K 
                 GGGSGGGSGGGS 
               
               
                 K512Y E515Q D570E 
                 BtagV7 
               
               
                   
               
               
                 A134S Y224K E239G V250I L253A A256S E375Y 
                 His10 
               
               
                 A437G A484E S487A D510K K512Y E515Q 
                 GGGSGGGSGGGS 
               
               
                   
                 BtagV7 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 4 
               
             
            
               
                   
               
               
                 Exemplary mutations introduced into an M2Y 
               
               
                 DNA polymerase. Positions are identified 
               
               
                 relative to SEQ ID NO: 2. 
               
            
           
           
               
               
            
               
                   
                 C-terminal 
               
               
                   
                 region 
               
               
                 Mutations 
                 feature(s) 
               
               
                   
               
               
                 K128E Y145I E236G V247I L250A S253A 
                 His10 
               
               
                 E372Y A434G A481E D507K K509Y E512Q 
                 GGGSGGGSGGGS 
               
               
                   
                 BtagV7 
               
               
                   
               
               
                 C103S K128E K132Q R172E E236G V247I 
                 His10 
               
               
                 L250A S253A E372Y A434G A481E E505R 
                 GGGSGGGSGGGS 
               
               
                 D507K K509Y E512Q 
                 BtagV7 
               
               
                   
               
            
           
         
       
     
     The amino acid sequences of exemplary recombinant Φ29 and M2Y polymerases harboring the exemplary mutation combinations of Tables 3 and 4 are provided in Tables 5 and 6. Table 5 includes the polymerase portion of the molecule as well as the one or more exogenous features at the C-terminal region of the polymerase, while Table 6 includes the amino acid sequence of the polymerase portion only. 
     
       
         
           
               
             
               
                 TABLE 5 
               
             
            
               
                   
               
               
                 Amino acid sequences of exemplary recombinant Φ29 and 
               
               
                 M2Y polymerases including C-terminal exogenous features. 
               
               
                 Amino acid positions are identified relative to SEQ ID 
               
               
                 NO: 1 for recombinant Φ29 polymerases (denoted by “Phi29”) 
               
               
                 or relative to SEQ ID NO: 2 for recombinant M2Y polymerases 
               
               
                 (denoted by “M2”). 
               
            
           
           
               
               
            
               
                 SEQ ID NO 
                 Amino Acid Sequence 
               
               
                   
               
               
                 7 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.K131E_L142K_Y 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 224K_D235E_E239G_V 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 250A_L253H_E375Y_A 
                 LGYKGKRKIHTVIYDSLKKLPFPVEKIAKDFKLTVKK 
               
               
                 437G_A484E_E508R_D 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 510K_K512Y_E515Q.Hi 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 s10.GGGSGGGSGGGS. 
                 KEVRKAYRGGFTWLNERFKGKEIGEGMVFDANSHY 
               
               
                 BtagV7 
                 PAQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCE 
               
               
                   
                 FELKEGYIPTIQIKRSRFYKGNEYLKSSGGEIADLWLS 
               
               
                   
                 NVDLELMKEHYDLYNVEYISGLKFKATTGLFKDFID 
               
               
                   
                 KWTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTG 
               
               
                   
                 KVPYLKENGALGFRLGEEETKDPVYTPMGVFITAWG 
               
               
                   
                 RYTTITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVD 
               
               
                   
                 PKKLGYWEHESTFKRAKYLRQKTYIQDIYMKRVKG 
               
               
                   
                 YLVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFK 
               
               
                   
                 VGFSRKMKPKPVQVPGGVVLVDDTFTIKGHHHHHH 
               
               
                   
                 HHHHGGGSGGGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 8 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.K131E_Y224K_E 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 239G_V250I_L253A_E3 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 75Y_A437G_C455A_A4 
                 LGYKGKRKIHTVIYDSLKKLPFPVEKIAKDFKLTVLK 
               
               
                 84E_D510K_K512Y_E5 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 15Q.His10.GGGSGGGS 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 GGGS.BtagV7 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                   
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                   
                 ELKEGYIPTIQIKRSRFYKGNEYLKSSGGEIADLWLSN 
               
               
                   
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYADTDSIHLTGTEIPDVIKDIVDP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKEVKGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDDTFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 9 
                 MKHMPRKMYSADFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.C11A_C106S_K13 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 1E_Y224K_E239G_L25 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIS 
               
               
                 3H_C290F_K337C_E37 
                 LGYKGKRKIHTVIYDSLKKLPFPVEKIAKDFKLTVLK 
               
               
                 5Y_A437G_C448V_A48 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 4E_D510K_K512Y_E51 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 5Q.His10.GGGSGGGSG 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDVNSHY 
               
               
                 GGS.BtagV7 
                 PAQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRFE 
               
               
                   
                 FELKEGYIPTIQIKRSRFYKGNEYLKSSGGEIADLWLS 
               
               
                   
                 NVDLELMCEHYDLYNVEYISGLKFKATTGLFKDFID 
               
               
                   
                 KWTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTG 
               
               
                   
                 KVPYLKENGALGFRLGEEETKDPVYTPMGVFITAWG 
               
               
                   
                 RYTTITAAQAVYDRIIYCDTDSIHLTGTEIPDVIKDIVD 
               
               
                   
                 PKKLGYWEHESTFKRAKYLRQKTYIQDIYMKEVKG 
               
               
                   
                 YLVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFK 
               
               
                   
                 VGFSRKMKPKPVQVPGGVVLVDDTFTIKGHHHHHH 
               
               
                   
                 HHHHGGGSGGGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 10 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.K131E_A134S_Y1 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 48I_Y224K_D235E_E23 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 9G_L253H_E375Y_A43 
                 LGYKGKRKIHTVIYDSLKKLPFPVEKISKDFKLTVLK 
               
               
                 7G_A484E_D510K_K51 
                 GDIDIHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 2Y_E515Q.His10.GGGS 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 GGGSGGGS.BtagV7 
                 KEVRKAYRGGFTWLNERFKGKEIGEGMVFDVNSHY 
               
               
                   
                 PAQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCE 
               
               
                   
                 FELKEGYIPTIQIKRSRFYKGNEYLKSSGGEIADLWLS 
               
               
                   
                 NVDLELMKEHYDLYNVEYISGLKFKATTGLFKDFID 
               
               
                   
                 KWTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTG 
               
               
                   
                 KVPYLKENGALGFRLGEEETKDPVYTPMGVFITAWG 
               
               
                   
                 RYTTITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVD 
               
               
                   
                 PKKLGYWEHESTFKRAKYLRQKTYIQDIYMKEVKG 
               
               
                   
                 YLVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFK 
               
               
                   
                 VGFSRKMKPKPVQVPGGVVLVDDTFTIKGHHHHHH 
               
               
                   
                 HHHHGGGSGGGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 11 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.K131E_Y148I_Y2 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 24K_E239G_V250I_L25 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 3A_E375Y_A437G_A48 
                 LGYKGKRKIHTVIYDSLKKLPFPVEKIAKDFKLTVLK 
               
               
                 4E_D510K_K512Y_E51 
                 GDIDIHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 5Q_D570E.His10.GGGS 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 GGGSGGGS.BtagV7 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                   
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                   
                 ELKEGYIPTIQIKRSRFYKGNEYLKS SGGEIADLWLSN 
               
               
                   
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVDP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKEVKGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDETFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 12 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.Q99W_K131E_Y1 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKI-DGAFI 
               
               
                 48I_Y224K_E239G_V25 
                 INWLERNGFKWSADGLPNTYNTIISRMGWWYMIDIC 
               
               
                 0I_L253A_E375Y_A437 
                 LGYKGKRKIHTVIYDSLKKLPFPVEKIAKDFKLTVLK 
               
               
                 G_A484E_D510K_K512 
                 GDIDIHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 Y_E515Q.His10.GGGSG 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 GGSGGGS.BtagV7 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                   
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                   
                 ELKEGYIPTIQIKRSRFYKGNEYLKSSGGEIADLWLSN 
               
               
                   
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVDP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKEVKGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDDTFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 13 
                 MSRKMFSCDFETTTKLDDCRVWAYGYMEIGNLDNY 
               
               
                 M2.K128E_Y145I_E236 
                 KIGNSLDEFMQWVMEIQADLYFHNLKFDGAFIVNWL 
               
               
                 G_V247I L250A_S253A_ 
                 EQHGFKWSNEGLPNTYNTIISKMGQWYMIDICFGYK 
               
               
                 E372Y_A434G_A481E_ 
                 GKRKLHTVIYDSLKKLPFPVEKIAKDFQLPLLKGDIDI 
               
               
                 D507K_K509Y_E512Q. 
                 HTERPVGHEITPEEYEYIKNDIEIIARALDIQFKQGLDR 
               
               
                 His10.GGGSGGGSGG 
                 MTAGSDSLKGFKDILSTKKFNKVFPKLSLPMDKEIRK 
               
               
                 GS.BtagV7 
                 AYRGGFTWLNDKYKGKEIGEGMVFDINSAYPAQMY 
               
               
                   
                 SRPLPYGAPIVFQGKYEKDEQYPLYIQRIRFEFELKEG 
               
               
                   
                 YIPTIQIKKNPFFKGNEYLKNSGVEPVELYLTNVDLEL 
               
               
                   
                 IQEHYELYNVEYIDGFKFREKTGLFKDFIDKWTYVKT 
               
               
                   
                 HEYGAKKQLAKLMLNSLYGKFASNPDVTGKVPYLK 
               
               
                   
                 DDGSLGFRVGDEEYKDPVYTPMGVFITAWGRFTTIT 
               
               
                   
                 AAQACYDRIIYCDTDSIHLTGTEVPEIIKDIVDPKKLG 
               
               
                   
                 YWEHESTFKRAKYLRQKTYIQDIYVKEVKGYLKQCS 
               
               
                   
                 PDEATTTKFSVKCAGMTDTIKKKVTFDNFAVGFSSM 
               
               
                   
                 GKPKPVQVNGGVVLVDSVFTIKGHHHHHHHHHHGG 
               
               
                   
                 GSGGGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 14 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.K131E_Y224K_E 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 239G_V250I_L253A_A2 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 56S_E375Y_A437G_C4 
                 LGYKGKRKIHTVIYDSLKKLPFPVEKIAKDFKLTVLK 
               
               
                 55A_A484E_D510K_K5 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 12Y_E515Q_F526L_D5 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 70E.His10.GGGSGGGS 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                 GGGS.BtagV7 
                 SQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                   
                 ELKEGYIPTIQIKRSRFYKGNEYLKSSGGEIADLWLSN 
               
               
                   
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYADTDSIHLTGTEIPDVIKDIVDP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKEVKGY 
               
               
                   
                 LVQGSPDDYTDIKLSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDETFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 15 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.Q99I_K131E_A13 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 4S_Y224K_E239G_V25 
                 INWLERNGFKWSADGLPNTYNTIISRMGIWYMIDICL 
               
               
                 0I_L253A_E375Y_A437 
                 GYKGKRKIHTVIYDSLKKLPFPVEKISKDFKLTVLKG 
               
               
                 N_A484E_E508R_D510 
                 DIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFKQ 
               
               
                 K_K512Y_E515Q_D570 
                 GLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLDK 
               
               
                 E.His10.GGGSGGGSGG 
                 EVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYPA 
               
               
                 GS.BtagV7 
                 QMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEFE 
               
               
                   
                 LKEGYIPTIQIKRSRFYKGNEYLKSSGGEIADLWLSNV 
               
               
                   
                 DLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDKW 
               
               
                   
                 TYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGKV 
               
               
                   
                 PYLKENGALGFRLGEEETKDPVYTPMGVFITAWNRY 
               
               
                   
                 TTITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVDPK 
               
               
                   
                 KLGYWEHESTFKRAKYLRQKTYIQDIYMKRVKGYL 
               
               
                   
                 VQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKVG 
               
               
                   
                 FSRKMKPKPVQVPGGVVLVDETFTIKGHHHHHHHH 
               
               
                   
                 HHGGGSGGGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 16 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.Q99I_K131E_A13 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 4S_Y224K_E239G_V25 
                 INWLERNGFKWSADGLPNTYNTIISRMGIWYMIDICL 
               
               
                 0I_L253A_R306Q_E375 
                 GYKGKRKIHTVIYDSLKKLPFPVEKISKDFKLTVLKG 
               
               
                 Y_A437N_A484E_E508 
                 DIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFKQ 
               
               
                 R_D510K_K512Y_E515 
                 GLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLDK 
               
               
                 Q_D570E.His10.GGGSG 
                 EVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYPA 
               
               
                 GGSGGGS.BtagV7 
                 QMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEFE 
               
               
                   
                 LKEGYIPTIQIKQSRFYKGNEYLKSSGGEIADLWLSN 
               
               
                   
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWNR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVDP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKRVKGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDETFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 17 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.K131E_Y224K_E 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKI-DGAFI 
               
               
                 239G_L253H_E375Y_M 
                 INWLERNGFKWS ADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 429A_A437G_C455A_A 
                 LGYKGKRKIHTVIYDSLKKLPFPVEKIAKDFKLTVLK 
               
               
                 484E_D510K_K512Y_E 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 515Q.His10.GGGSGGG 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 SGGGS.BtagV7 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDVNSHY 
               
               
                   
                 PAQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCE 
               
               
                   
                 FELKEGYIPTIQIKRSRFYKGNEYLKS SGGEIADLWLS 
               
               
                   
                 NVDLELMKEHYDLYNVEYISGLKFKATTGLFKDFID 
               
               
                   
                 KWTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTG 
               
               
                   
                 KVPYLKENGALGFRLGEEETKDPVYTPAGVFITAWG 
               
               
                   
                 RYTTITAAQACYDRIIYADTDSIHLTGTEIPDVIKDIVD 
               
               
                   
                 PKKLGYWEHESTFKRAKYLRQKTYIQDIYMKEVKG 
               
               
                   
                 YLVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFK 
               
               
                   
                 VGFSRKMKPKPVQVPGGVVLVDDTFTIKGHHHHHH 
               
               
                   
                 HHHHGGGSGGGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 18 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.K131E_Y148I_Y2 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 24K_E239G_V250I_L25 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 3A_E375Y_A437G_A48 
                 LGYKGKRKIHTVIYDSLKKLPFPVEKIAKDFKLTVLK 
               
               
                 4E_D510K_K512Y_E51 
                 GDIDIHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 5Q.His10.GGGSGGGSG 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 GGS 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                   
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                   
                 ELKEGYIPTIQIKRSRFYKGNEYLKSSGGEIADLWLSN 
               
               
                   
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVDP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKEVKGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDDTFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGS 
               
               
                   
               
               
                 19 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.K131E_A134S_Y2 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 24K_E239G_V250I_L25 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 3A_E375Y_A437N_A48 
                 LGYKGKRKIHTVIYDSLKKLPFPVEKISKDFKLTVLK 
               
               
                 4E_E508R_D510K_K51 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 2Y_E515Q_D570E.His1 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 0.GGGSGGGSGGGS.Bt 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                 agV7 
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                   
                 ELKEGYIPTIQIKRSRFYKGNEYLKSSGGEIADLWLSN 
               
               
                   
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWNR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVDP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKRVKGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDETFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 20 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.K131E_Y148I_Y2 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 24K_E239G_V250I_L25 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 3A_E375Y_A437G_A48 
                 LGYKGKRKIHTVIYDSLKKLPFPVEKIAKDFKLTVLK 
               
               
                 4E_H485Q_D510K_K51 
                 GDIDIHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 2Y_E515Q.His10.GGGS 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 GGGSGGGS.BtagV7 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                   
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                   
                 ELKEGYIPTIQIKRSRFYKGNEYLKSSGGEIADLWLSN 
               
               
                   
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVDP 
               
               
                   
                 KKLGYWEQESTFKRAKYLRQKTYIQDIYMKEVKGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDDTFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 21 
                 MSRKMFSCDFETTTKLDDCRVWAYGYMEIGNLDNY 
               
               
                 M2.C103S_K128E_K132 
                 KIGNSLDEFMQWVMEIQADLYFHNLKFDGAFIVNWL 
               
               
                 Q_R172E_E236G_V247I_ 
                 EQHGFKWSNEGLPNTYNTIISKMGQWYMIDISFGYK 
               
               
                 L250A_S253A_E372Y_ 
                 GKRKLHTVIYDSLKKLPFPVEKIAQDFQLPLLKGDID 
               
               
                 A434G_A481E_E505R_ 
                 YHTERPVGHEITPEEYEYIKNDIEIIAEALDIQFKQGLD 
               
               
                 D507K_K509Y_E512Q. 
                 RMTAGSDSLKGFKDILSTKKFNKVFPKLSLPMDKEIR 
               
               
                 His10.GGGSGGGSGG 
                 KAYRGGFTWLNDKYKGKEIGEGMVFDINSAYPAQM 
               
               
                 GS.BtagV7 
                 YSRPLPYGAPIVFQGKYEKDEQYPLYIQRIRFEFELKE 
               
               
                   
                 GYIPTIQIKKNPFFKGNEYLKNSGVEPVELYLTNVDL 
               
               
                   
                 ELIQEHYELYNVEYIDGFKFREKTGLFKDFIDKWTYV 
               
               
                   
                 KTHEYGAKKQLAKLMLNSLYGKFASNPDVTGKVPY 
               
               
                   
                 LKDDGSLGFRVGDEEYKDPVYTPMGVFITAWGRFTT 
               
               
                   
                 ITAAQACYDRIIYCDTDSIHLTGTEVPEIIKDIVDPKKL 
               
               
                   
                 GYWEHESTFKRAKYLRQKTYIQDIYVKRVKGYLKQ 
               
               
                   
                 CSPDEATTTKFSVKCAGMTDTIKKKVTFDNFAVGFSS 
               
               
                   
                 MGKPKPVQVNGGVVLVDSVFTIKGHHHHHHHHHH 
               
               
                   
                 GGGSGGGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 22 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.K131E_Y148I_Y2 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 24K_E239G_V250I_L25 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 3A_E375Y_M429A_A43 
                 LGYKGKRKIHTVIYDSLKKLPFPVEKIAKDFKLTVLK 
               
               
                 7G_A484E_D510K_K51 
                 GDIDIHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 2Y_E515Q.His10.GGGS 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 GGGSGGGS.BtagV7 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                   
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                   
                 ELKEGYIPTIQIKRSRFYKGNEYLKSSGGEIADLWLSN 
               
               
                   
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPAGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVDP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKEVKGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDDTFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 23 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.V141K_L142K_Y 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 224K E239G_V250I_L2 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 53A_A256S_R306Q_R3 
                 LGYKGKRKIHTVIYDSLKKLPFPVKKIAKDFKLTKKK 
               
               
                 08L_K311E_E375Y_A4 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 37G_T441I_A484E_S48 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 7A_E508R_D510K_K51 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                 2Y_E515Q.His10.GGGS 
                 SQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                 GGGSGGGS.BtagV7 
                 ELKEGYIPTIQIKQSLFYEGNEYLKSSGGEIADLWLSN 
               
               
                   
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTIITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVDP 
               
               
                   
                 KKLGYWEHEATFKRAKYLRQKTYIQDIYMKRVKGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDDTFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 24 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.Y224K_E239G_V 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 250I_L253A_A256S_E3 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 75Y_A437G_A484E_S4 
                 LGYKGKRKIHTVIYDSLKKLPFPVKKIAKDFKLTVLK 
               
               
                 87A_D510K_K512Y_E5 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 15Q.His10.GGGSGGGS 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 GGGS.BtagV7 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                   
                 SQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                   
                 ELKEGYIPTIQIKRSRFYKGNEYLKSSGGEIADLWLSN 
               
               
                   
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVDP 
               
               
                   
                 KKLGYWEHEATFKRAKYLRQKTYIQDIYMKEVKGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDDTFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 25 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.V141K_L142K_Y 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 224K_E239G_V250I_L2 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 53A_A256S_E375Y_A4 
                 LGYKGKRKIHTVIYDSLKKLPFPVKKIAKDFKLTKKK 
               
               
                 37G_T441I_A484E_S48 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 7A_E508R_D510K_K51 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 2Y_E515Q_D570E.His1 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                 0.GGGSGGGSGGGS.Bt 
                 SQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                 agV7 
                 ELKEGYIPTIQIKRSRFYKGNEYLKSSGGEIADLWLSN 
               
               
                   
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTIITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVDP 
               
               
                   
                 KKLGYWEHEATFKRAKYLRQKTYIQDIYMKRVKGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDETFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 26 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.A134S_Y224K_E2 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 39G_V250I_L253A_A25 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 6S_E375Y_A437G_A48 
                 LGYKGKRKIHTVIYDSLKKLPFPVKKISKDFKLTVLK 
               
               
                 4E_S487A_D510K_K51 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 2Y_E515Q.His10.GGGS 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 GGGSGGGS.BtagV7 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                   
                 SQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                   
                 ELKEGYIPTIQIKRSRFYKGNEYLKSSGGEIADLWLSN 
               
               
                   
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVDP 
               
               
                   
                 KKLGYWEHEATFKRAKYLRQKTYIQDIYMKEVKGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDDTFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 6 
               
             
            
               
                   
               
               
                 Amino acid sequences of exemplary recombinant Φ29 and 
               
               
                 M2Y polymerases. Amino acid positions are identified 
               
               
                 relative to SEQ ID NO: 1 for recombinant Φ29 polymerases 
               
               
                 (denoted by “Phi29”) or relative to SEQ ID NO: 2 for 
               
               
                 recombinant M2Y polymerases (denoted by “M2”). 
               
            
           
           
               
               
            
               
                 SEQ ID NO 
                 Amino Acid Sequence 
               
               
                   
               
               
                 27 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.K131E_L142K_Y 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 224K_D235E_E239G_V 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 250A_L253H_E375Y_A 
                 LGYKGKRKIHTVIYDSLKKLPFPVEKIAKDFKLTVKK 
               
               
                 437G_A484E_E508R_D 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 510K_K512Y_E515Q 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                   
                 KEVRKAYRGGFTWLNERFKGKEIGEGMVFDANSHY 
               
               
                   
                 PAQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCE 
               
               
                   
                 FELKEGYIPTIQIKRSRFYKGNEYLKSSGGEIADLWLS 
               
               
                   
                 NVDLELMKEHYDLYNVEYISGLKFKATTGLFKDFID 
               
               
                   
                 KWTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTG 
               
               
                   
                 KVPYLKENGALGFRLGEEETKDPVYTPMGVFITAWG 
               
               
                   
                 RYTTITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVD 
               
               
                   
                 PKKLGYWEHESTFKRAKYLRQKTYIQDIYMKRVKG 
               
               
                   
                 YLVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFK 
               
               
                   
                 VGFSRKMKPKPVQVPGGVVLVDDTFTIK 
               
               
                   
               
               
                 28 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.K131E_Y224K_E 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 239G_V250I_L253A_E3 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 75Y_A437G_C455A_A4 
                 LGYKGKRKIHTVIYDSLKKLPFPVEKIAKDFKLTVLK 
               
               
                 84E_D510K_K512Y_E5 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 15Q 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                   
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                   
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                   
                 ELKEGYIPTIQIKRSRFYKGNEYLKSSGGEIADLWLSN 
               
               
                   
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYADTDSIHLTGTEIPDVIKDIVDP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKEVKGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDDTFTIK 
               
               
                   
               
               
                 29 
                 MKHMPRKMYSADFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.C11A_C1065_K13 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 1E_Y224K_E239G_L25 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIS 
               
               
                 3H_C290F_K337C_E37 
                 LGYKGKRKIHTVIYDSLKKLPFPVEKIAKDFKLTVLK 
               
               
                 5Y_A437G_C448V_A48 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 4E_D510K_K512Y_E51 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 5Q 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDVNSHY 
               
               
                   
                 PAQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRFE 
               
               
                   
                 FBLKEGYIPTIQIKRSRFYKGNEYLKSSGGEIADLWLS 
               
               
                   
                 NVDLELMCEHYDLYNVEYISGLKFKATTGLFKDFID 
               
               
                   
                 KWTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTG 
               
               
                   
                 KVPYLKENGALGIRLGEEETKDPVYTPMGVFITAWG 
               
               
                   
                 RYTTITAAQAVYDRIIYCDTDSIHLTGTEIPDVIKDIVD 
               
               
                   
                 PKKLGYWEHESTFKRAKYLRQKTYIQDIYMKEVKG 
               
               
                   
                 YLVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFK 
               
               
                   
                 VGFSRKMKPKPVQVPGGVVLVDDTFTIK 
               
               
                   
               
               
                 30 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.K131E_A134S_Y1 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 48I_Y224K_D235E_E23 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 9G_L253H_E375Y_A43 
                 LGYKGKRKIHTVIYDSLKKLPFPVEKISKDFKLTVLK 
               
               
                 7G_A484E_D510K_K51 
                 GDIDIHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 2Y_E515Q 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                   
                 KEVRKAYRGGFTWLNERFKGKEIGEGMVFDVNSHY 
               
               
                   
                 PAQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCE 
               
               
                   
                 FELKEGYIPTIQIKRSRFYKGNEYLKSSGGEIADLWLS 
               
               
                   
                 NVDLELMKEHYDLYNVEYISGLKFKATTGLFKDFID 
               
               
                   
                 KWTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTG 
               
               
                   
                 KVPYLKENGALGFRLGEEETKDPVYTPMGVFITAWG 
               
               
                   
                 RYTTITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVD 
               
               
                   
                 PKKLGYWEHESTFKRAKYLRQKTYIQDIYMKEVKG 
               
               
                   
                 YLVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFK 
               
               
                   
                 VGFSRKMKPKPVQVPGGVVLVDDTFTIK 
               
               
                   
               
               
                 31 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.K131E_Y148I_Y2 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 24K_E239G_V250I_L25 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 3A_E375Y_A437G_A48 
                 LGYKGKRKIHTVIYDSLKKLPFPVEKIAKDFKLTVLK 
               
               
                 4E_D510K_K512Y_E51 
                 GDIDIHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 5Q_D570E 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                   
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                   
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                   
                 ELKEGYIPTIQIKRSRFYKGNEYLKS SGGEIADLWLSN 
               
               
                   
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVDP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKEVKGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDETFTIK 
               
               
                   
               
               
                 32 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.Q99W_K131E_Y1 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 48I_Y224K_E239G_V25 
                 INWLERNGFKWSADGLPNTYNTIISRMGWWYMIDIC 
               
               
                 0I_L253A_E375Y_A437 
                 LGYKGKRKIHTVIYDSLKKLPFPVEKIAKDFKLTVLK 
               
               
                 G_A484E_D510K_K512 
                 GDIDIHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 Y_E515Q 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                   
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                   
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                   
                 ELKEGYIPTIQIKRSRFYKGNEYLKSSGGEIADLWLSN 
               
               
                   
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVDP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKEVKGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDDTFTIK 
               
               
                   
               
               
                 33 
                 MSRKMFSCDFETTTKLDDCRVWAYGYMEIGNLDNY 
               
               
                 M2.K128E_Y145I_E236 
                 KIGNSLDEFMQWVMEIQADLYFHNLKFDGAFIVNWL 
               
               
                 G_V247I_L250A_S253A_ 
                 EQHGFKWSNEGLPNTYNTIISKMGQWYMIDICFGYK 
               
               
                 E372Y_A434G_A481E_ 
                 GKRKLHTVIYDSLKKLPFPVEKIAKDFQLPLLKGDIDI 
               
               
                 D507K_K509Y_E512Q 
                 HTERPVGHEITPEEYEYIKNDIEIIARALDIQFKQGLDR 
               
               
                   
                 MTAGSDSLKGFKDILSTKKFNKVFPKLSLPMDKEIRK 
               
               
                   
                 AYRGGFTWLNDKYKGKEIGEGMVFDINSAYPAQMY 
               
               
                   
                 SRPLPYGAPIVFQGKYEKDEQYPLYIQRIRFEFELKEG 
               
               
                   
                 YIPTIQIKKNPFFKGNEYLKNSGVEPVELYLTNVDLEL 
               
               
                   
                 IQEHYELYNVEYIDGFKFREKTGLFKDFIDKWTYVKT 
               
               
                   
                 HEYGAKKQLAKLMLNSLYGKFASNPDVTGKVPYLK 
               
               
                   
                 DDGSLGFRVGDEEYKDPVYTPMGVFITAWGRFTTIT 
               
               
                   
                 AAQACYDRIIYCDTDSIHLTGTEVPEIIKDIVDPKKLG 
               
               
                   
                 YWEHESTFKRAKYLRQKTYIQDIYVKEVKGYLKQCS 
               
               
                   
                 PDEATTTKFSVKCAGMTDTIKKKVTFDNFAVGFSSM 
               
               
                   
                 GKPKPVQVNGGVVLVDSVFTIK 
               
               
                 34 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.K131E_Y224K_E 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 239G_V250I_L253A_A2 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 56S_E375Y_A437G_C4 
                 LGYKGKRKIHTVIYDSLKKLPFPVEKIAKDFKLTVLK 
               
               
                 55A_A484E_D510K_K5 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 12Y_E515Q_F526L_D5 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 70E 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                   
                 SQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                   
                 ELKEGYIPTIQIKRSRFYKGNEYLKSSGGEIADLWLSN 
               
               
                   
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYADTDSIHLTGTEIPDVIKDIVDP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKEVKGY 
               
               
                   
                 LVQGSPDDYTDIKLSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDETFTIK 
               
               
                   
               
               
                 35 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.Q99I_K131E_A13 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 45_Y224K_E239G_V25 
                 INWLERNGFKWSADGLPNTYNTIISRMGIWYMIDICL 
               
               
                 0I_L253A_E375Y_A437 
                 GYKGKRKIHTVIYDSLKKLPFPVEKISKDFKLTVLKG 
               
               
                 N_A484E_E508R_D510 
                 DIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFKQ 
               
               
                 K_K512Y_E515Q_D570 
                 GLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLDK 
               
               
                 E 
                 EVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYPA 
               
               
                   
                 QMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEFE 
               
               
                   
                 LKEGYIPTIQIKRSRFYKGNEYLKSSGGEIADLWLSNV 
               
               
                   
                 DLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDKW 
               
               
                   
                 TYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGKV 
               
               
                   
                 PYLKENGALGFRLGEEETKDPVYTPMGVFITAWNRY 
               
               
                   
                 TTITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVDPK 
               
               
                   
                 KLGYWEHESTFKRAKYLRQKTYIQDIYMKRVKGYL 
               
               
                   
                 VQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKVG 
               
               
                   
                 FSRKMKPKPVQVPGGVVLVDETFTIK 
               
               
                   
               
               
                 36 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.Q99I_K131E_A13 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKIDGAFI 
               
               
                 4S_Y224K_E239G_V25 
                 INWLERNGFKWSADGLPNTYNTIISRMGIWYMIDICL 
               
               
                 0I_L253A_R306Q_E375 
                 GYKGKRKIHTVIYDSLKKLPFPVEKISKDFKLTVLKG 
               
               
                 Y_A437N_A484E_E508 
                 DIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFKQ 
               
               
                 R_D510K_K512Y_E515 
                 GLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLDK 
               
               
                 Q_D570E 
                 EVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYPA 
               
               
                   
                 QMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEFE 
               
               
                   
                 LKEGYIPTIQIKQSRFYKGNEYLKSSGGEIADLWLSN 
               
               
                   
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWNR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVDP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKRVKGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDETFTIK 
               
               
                   
               
               
                 37 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.K131E_Y224K_E 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 239G_L253H_E375Y_M 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 429A_A437G_C455A_A 
                 LGYKGKRKIHTVIYDSLKKLPFPVEKIAKDFKLTVLK 
               
               
                 484E_D510K_K512Y_E 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 515Q 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                   
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDVNSHY 
               
               
                   
                 PAQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCE 
               
               
                   
                 FELKEGYIPTIQIKRSRFYKGNEYLKSSGGEIADLWLS 
               
               
                   
                 NVDLELMKEHYDLYNVEYISGLKFKATTGLFKDFID 
               
               
                   
                 KWTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTG 
               
               
                   
                 KVPYLKENGALGFRLGEEETKDPVYTPAGVFITAWG 
               
               
                   
                 RYTTITAAQACYDRIIYADTDSIHLTGTEIPDVIKDIVD 
               
               
                   
                 PKKLGYWEHESTFKRAKYLRQKTYIQDIYMKEVKG 
               
               
                   
                 YLVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFK 
               
               
                   
                 VGFSRKMKPKPVQVPGGVVLVDDTFTIK 
               
               
                   
               
               
                 38 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.K131E_Y148I_Y2 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 24K_E239G_V250I_L25 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 3A_E375Y_A437G_A48 
                 LGYKGKRKIHTVIYDSLKKLPFPVEKIAKDFKLTVLK 
               
               
                 4E_D510K_K512Y_E51 
                 GDIDIHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 5Q 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                   
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                   
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                   
                 ELKEGYIPTIQIKRSRFYKGNEYLKSSGGEIADLWLSN 
               
               
                   
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVDP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKEVKGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDDTFTIK 
               
               
                   
               
               
                 39 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.K131E_A134S_Y2 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKI-DGAFI 
               
               
                 24K_E239G_V250I_L25 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 3A_E375Y_A437N_A48 
                 LGYKGKRKIHTVIYDSLKKLPFPVEKISKDFKLTVLK 
               
               
                 4E_E508R_D510K_K51 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 2Y_E515Q_D570E 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                   
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                   
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                   
                 ELKEGYIPTIQIKRSRFYKGNEYLKSSGGEIADLWLSN 
               
               
                   
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWNR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVDP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKRVKGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDETFTIK 
               
               
                   
               
               
                 40 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.K131E_Y148I_Y2 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 24K_E239G V250I_L25 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 3A_E375Y_A437G_A48 
                 LGYKGKRKIHTVIYDSLKKLPFPVEKIAKDFKLTVLK 
               
               
                 4E_H485Q_D510K_K51 
                 GDIDIHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 2Y_E515Q 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                   
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                   
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                   
                 ELKEGYIPTIQIKRSRFYKGNEYLKSSGGEIADLWLSN 
               
               
                   
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVDP 
               
               
                   
                 KKLGYWEQESTFKRAKYLRQKTYIQDIYMKEVKGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDDTFTIK 
               
               
                   
               
               
                 41 
                 MSRKMFSCDFETTTKLDDCRVWAYGYMEIGNLDNY 
               
               
                 M2.C103S_K128E_K132 
                 KIGNSLDEFMQWVMEIQADLYFHNLKFDGAFIVNWL 
               
               
                 Q_R172E_E236G_V247I_ 
                 EQHGFKWSNEGLPNTYNTIISKMGQWYMIDISFGYK 
               
               
                 L250A S253A_E372Y_ 
                 GKRKLHTVIYDSLKKLPFPVEKIAQDFQLPLLKGDID 
               
               
                 A434G A481E E505R_ 
                 YHTERPVGHEITPEEYEYIKNDIEIIAEALDIQFKQGLD 
               
               
                 D507K_K509Y_E512Q 
                 RMTAGSDSLKGFKDILSTKKFNKVFPKLSLPMDKEIR 
               
               
                   
                 KAYRGGFTWLNDKYKGKEIGEGMVFDINSAYPAQM 
               
               
                   
                 YSRPLPYGAPIVFQGKYEKDEQYPLYIQRIRFEFELKE 
               
               
                   
                 GYIPTIQIKKNPFFKGNEYLKNSGVEPVELYLTNVDL 
               
               
                   
                 ELIQEHYELYNVEYIDGFKFREKTGLFKDFIDKWTYV 
               
               
                   
                 KTHEYGAKKQLAKLMLNSLYGKFASNPDVTGKVPY 
               
               
                   
                 LKDDGSLGFRVGDEEYKDPVYTPMGVFITAWGRFTT 
               
               
                   
                 ITAAQACYDRIIYCDTDSIHLTGTEVPEIIKDIVDPKKL 
               
               
                   
                 GYWEHESTFKRAKYLRQKTYIQDIYVKRVKGYLKQ 
               
               
                   
                 CSPDEATTTKFSVKCAGMTDTIKKKVTFDNFAVGFSS 
               
               
                   
                 MGKPKPVQVNGGVVLVDSVFTIK 
               
               
                   
               
               
                 42 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.K131E_Y148I_Y2 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 24K_E239G_V250I_L25 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 3A_E375Y_M429A_A43 
                 LGYKGKRKIHTVIYDSLKKLPFPVEKIAKDFKLTVLK 
               
               
                 7G_A484E_D510K_K51 
                 GDIDIHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 2Y_E515Q 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                   
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                   
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                   
                 ELKEGYIPTIQIKRSRFYKGNEYLKSSGGEIADLWLSN 
               
               
                   
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPAGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVDP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKEVKGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDDTFTIK 
               
               
                   
               
               
                 43 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.V141K_L142K_Y 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 224K_E239G_V250I_L2 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 53A_A256S_R306Q_R3 
                 LGYKGKRKIHTVIYDSLKKLPFPVKKIAKDFKLTKKK 
               
               
                 08L_K311E_E375Y_A4 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 37G_T441I_A484E_S48 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 7A_E508R_D510K_K51 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                 2Y_E515Q 
                 SQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                   
                 ELKEGYIPTIQIKQSLFYEGNEYLKSSGGEIADLWLSN 
               
               
                   
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTIITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVDP 
               
               
                   
                 KKLGYWEHEATFKRAKYLRQKTYIQDIYMKRVKGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDDTFTIK 
               
               
                   
               
               
                 44 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.Y224K_E239G_V 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 250I_L253A_A256S_E3 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 75Y_A437G_A484E_S4 
                 LGYKGKRKIHTVIYDSLKKLPFPVKKIAKDFKLTVLK 
               
               
                 87A_D510K_K512Y_E5 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 15Q 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                   
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                   
                 SQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                   
                 ELKEGYIPTIQIKRSRFYKGNEYLKSSGGEIADLWLSN 
               
               
                   
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVDP 
               
               
                   
                 KKLGYWEHEATFKRAKYLRQKTYIQDIYMKEVKGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDDTFTIK 
               
               
                   
               
               
                 45 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.V141K_L142K_Y 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 224K_E239G_V250I_L2 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 53A_A256S_E375Y_A4 
                 LGYKGKRKIHTVIYDSLKKLPFPVKKIAKDFKLTKKK 
               
               
                 37G_T441I_A484E_S48 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 7A_E508R_D510K_K51 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 2Y_E515Q_D570E 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                   
                 SQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                   
                 ELKEGYIPTIQIKRSRFYKGNEYLKS SGGEIADLWLSN 
               
               
                   
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTS YGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTIITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVDP 
               
               
                   
                 KKLGYWEHEATFKRAKYLRQKTYIQDIYMKRVKGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDETFTIK 
               
               
                   
               
               
                 46 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.A134S_Y224K_E2 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 39G_V250I_L253A_A25 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 6S_E375Y_A437G_A48 
                 LGYKGKRKIHTVIYDSLKKLPFPVKKISKDFKLTVLK 
               
               
                 4E_S487A_D510K_K51 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 2Y_E515Q 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                   
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                   
                 SQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                   
                 ELKEGYIPTIQIKRSRFYKGNEYLKS SGGEIADLWLSN 
               
               
                   
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVDP 
               
               
                   
                 KKLGYWEHEATFKRAKYLRQKTYIQDIYMKEVKGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDDTFTIK 
               
               
                   
               
            
           
         
       
     
     A list of additional exemplary polymerase mutation combinations, and optional corresponding exogenous or heterologous features at the C-terminal region of the polymerase, is provided in Tables 7 and 8. These combinations can enhance performance of the polymerase with large analogs (e.g., protein shield analogs, other shielded analogs, or other analogs with a molecular weight of at least 10,000), e.g., in single molecule sequencing. Positions of amino acid substitutions are identified relative to a wild-type Φ29 DNA polymerase (SEQ ID NO:1) for the recombinant polymerases in Table 7 and relative to a wild-type M2Y DNA polymerase (SEQ ID NO:2) for the recombinant polymerase in Table 8. Polymerases of the invention (including those provided in Tables 7 and 8) can include any exogenous or heterologous feature (or combination of such features), e.g., at the N- and/or C-terminal region. For example, some or all of the exogenous features listed in Tables 7 and 8 can be omitted, or substituted or combined with any of the other exogenous features described herein, and still result in a polymerase of the invention. As will be appreciated, the numbering of amino acid residues is with respect to a particular reference polymerase, such as the wild-type sequence of the Φ29 polymerase (SEQ ID NO:1) or M2Y polymerase (SEQ ID NO:2); actual position of a mutation within a molecule of the invention may vary based upon the nature of the various modifications that the enzyme includes relative to the wild type Φ29 enzyme, e.g., deletions and/or additions to the molecule, either at the termini or within the molecule itself. 
     
       
         
           
               
             
               
                 TABLE 7 
               
             
            
               
                   
               
               
                 Exemplary mutations introduced into a Φ29 DNA 
               
               
                 polymerase. Positions are identified relative 
               
               
                 to SEQ ID NO: l. 
               
            
           
           
               
               
            
               
                   
                 C-terminal region 
               
               
                 Mutations 
                 feature(s) 
               
               
                   
               
               
                 Y224K E239G V250I L253A E375Y A437G A484E 
                 His10 
               
               
                 E508R D510K K512Y E515Q D570M 
                 GGGSGGGSGGGS 
               
               
                   
                 BtagV7 
               
               
                   
               
               
                 A134S Y224K E239G V250I L253A E375Y A437G 
                 His10 
               
               
                 A484E 5487A E508R D510K K512Y E515Q I524S 
                 GGGSGGGSGGGS 
               
               
                 F526L D570E 
                 BtagV7 
               
               
                   
               
               
                 L142K Y224K E239G V250I L253A E375Y A437G 
                 His10 
               
               
                 D476H A484E E508R D510K K512Y L513K E515Q 
                 GGGSGGGSGGGS 
               
               
                 D570E 
                 BtagV7 
               
               
                   
                 GGGSGGGSGGGS 
               
               
                   
                 BtagV7 
               
               
                   
               
               
                 L142K Y224K E239G V250I L253A R306Q R308L 
                 His10 
               
               
                 E375Y A437G D476H A484E E508R D510K K512Y 
                 GGGSGGGSGGGS 
               
               
                 L513K E515Q D570E 
                 BtagV7 
               
               
                   
                 GGGSGGGSGGGS 
               
               
                   
                 BtagV7 
               
               
                   
               
               
                 L142K Y224K E239G V250I L253A R306Q R308L 
                 His10 
               
               
                 E375Y A437G E466K D476H A484E E508R D510K 
                 GGGSGGGSGGGS 
               
               
                 K512Y L513K E515Q D570E 
                 BtagV7 
               
               
                   
                 GGGSGGGSGGGS 
               
               
                   
                 BtagV7 
               
               
                   
               
               
                 L142K Y224K E239G V250I L253A R306Q R308L 
                 His10 
               
               
                 E375Y A437G E466K D476H A484E E508R D510K 
                 GGGSGGGSGGGS 
               
               
                 K512Y E515Q D570E 
                 BtagV7 
               
               
                   
                 GGGSGGGSGGGS 
               
               
                   
                 BtagV7 
               
               
                   
               
               
                 L142K Y224K E239G V250I L253A E375Y A437G 
                 His10 
               
               
                 E466K D476H A484E E508R D510K K512Y E515Q 
                 GGGSGGGSGGGS 
               
               
                 D570E 
                 BtagV7 
               
               
                   
                 GGGSGGGSGGGS 
               
               
                   
                 BtagV7 
               
               
                   
               
               
                 L142K Y224K E239G V250I L253A E375Y M429A 
                 His10 
               
               
                 A437G A484E E508R D510K K512Y E515Q D570E 
                 GGGSGGGSGGGS 
               
               
                   
                 BtagV7 
               
               
                   
                 GGGSGGGSGGGS 
               
               
                   
                 BtagV7 
               
               
                   
               
               
                 A134S L142K Y224K E239G V250I L253A E375Y 
                 His10 
               
               
                 A437G A484E S487A E508R D510K K512Y E515Q 
                 GGGSGGGSGGGS 
               
               
                 I524S F526L D570E 
                 BtagV7 
               
               
                   
               
               
                 L142K Y224K D235E E239G V250A L253H E375Y 
                 His10 
               
               
                 A437G A484E E508R D510K K512Y E515Q D570E 
                 GGGSGGGSGGGS 
               
               
                   
                 BtagV7 
               
               
                   
               
               
                 Y224K E239G V2501 L253A E375Y A437G A484E 
                 His10 
               
               
                 E508R D510K K512Y E515Q 
                 GGGSGGGSGGGS 
               
               
                   
                 BtagV7 
               
               
                   
               
               
                 V141K L142K Y224K E239G V250I L253A E375Y 
                 His10 
               
               
                 A437G A484E E508R D510K K512Y E515Q 
                 GGGSGGGSGGGS 
               
               
                   
                 BtagV7 
               
               
                   
               
               
                 Y224K E239G V250I L253A E375Y A437G A484E 
                 His10 
               
               
                 S487A E508R D510K K512Y E515Q I524S F526L 
                 GGGSGGGSGGGS 
               
               
                 D570M 
                 BtagV7 
               
               
                   
               
               
                 K135Q L142K Y224K E239G V250I L253A R306Q 
                 His10 
               
               
                 R308L E375Y A437G E466K D476H A484E E508R 
                 GGGSGGGSGGGS 
               
               
                 D51OR K512Y E515Q D570S T571V 
                 BtagV7 
               
               
                   
                 GGGSGGGSGGGS 
               
               
                   
                 BtagV7 
               
               
                   
               
               
                 K131E K135Q L142K Y224K E239G V250I L253A 
                 His10 
               
               
                 E375Y A437G A484E E508R D51OR K512Y E515Q 
                 GGGSGGGSGGGS 
               
               
                 D523R P558A D570S T571V 
                 BtagV7 
               
               
                   
                 GGGSGGGSGGGS 
               
               
                   
                 BtagV7 
               
               
                   
               
               
                 A49E C106S K114R K131E K135Q L142K Y224K 
                 His10 
               
               
                 E239G V2501 L253A Y369E E375Y A437G D476H 
                 GGGSGGGSGGGS 
               
               
                 A484E E508R D510K K512Y E515Q D523R D570S 
                 BtagV7 
               
               
                 T571V 
                 GGGSGGGSGGGS 
               
               
                   
                 BtagV7 
               
               
                   
               
               
                 K135Q K138Q L142K Y224K E239G V250I L253A 
                 His10 
               
               
                 R306Q R308L E375Y A437G E466K D476H A484E 
                 GGGSGGGSGGGS 
               
               
                 E508R D510K K512Y E515Q I524T P558A D570S 
                 BtagV7 
               
               
                 T571V 
                 GGGSGGGSGGGS 
               
               
                   
                 BtagV7 
               
               
                   
               
               
                 K135Q K138Q L142K Y224K E239G V250I L253A 
                 His10 
               
               
                 R306Q R308L E375Y A437G E466K V4751 D476H 
                 GGGSGGGSGGGS 
               
               
                 A484E E508R D510K K512Y E515Q I524T P558A 
                 BtagV7 
               
               
                 D570S T571V 
                 GGGSGGGSGGGS 
               
               
                   
                 BtagV7 
               
               
                   
               
               
                 K135Q K138Q L142K Y224K E239G V250I L253A 
                 His10 
               
               
                 R306Q R308L T368S E375Y A437G E466K D476H 
                 GGGSGGGSGGGS 
               
               
                 A484E E508R D510K K512Y E515Q I524T P558A 
                 BtagV7 
               
               
                 D570S T571V 
                 GGGSGGGSGGGS 
               
               
                   
                 BtagV7 
               
               
                   
               
               
                 K135Q K138Q L142K Y224K E239G V250I L253A 
                 His10 
               
               
                 R306Q R308L T368S E375Y A437G E466K V475I 
                 GGGSGGGSGGGS 
               
               
                 D476H A484E E508R D510K K512Y E515Q P558A 
                 BtagV7 
               
               
                 D570S T571V 
                 GGGSGGGSGGGS 
               
               
                   
                 BtagV7 
               
               
                   
               
               
                 L44A K135Q K138Q L142K Y224K E239G V250I 
                 His10 
               
               
                 L253A R306Q R308L E375Y A437G E466K D476H 
                 GGGSGGGSGGGS 
               
               
                 A484E S487A E508R D510K K512Y E515Q P558A 
                 BtagV7 
               
               
                 D570S T571V 
                 GGGSGGGSGGGS 
               
               
                   
                 BtagV7 
               
               
                   
               
               
                 K135Q L142K Y224K E239G V250I L253A R306Q 
                 His10 
               
               
                 R308L T368S E375Y A437G E466K D476H A484E 
                 GGGSGGGSGGGS 
               
               
                 E508R D510R K512Y E515Q P558A D570S T571V 
                 BtagV7 
               
               
                   
                 GGGSGGGSGGGS 
               
               
                   
                 BtagV7 
               
               
                   
               
               
                 A49E C106S K114R K135Q L142K Y224K E239G 
                 His10 
               
               
                 V2501 L253A R306Q R308L E375Y A437G E466K 
                 GGGSGGGSGGGS 
               
               
                 D476H A484E E508R D510R K512Y E515Q K536Q 
                 BtagV7 
               
               
                 K539Q D570S T571V 
                 GGGSGGGSGGGS 
               
               
                   
                 BtagV7 
               
               
                   
               
               
                 L44A K135Q K138Q L142K Y224K E239G V250I 
                 His10 
               
               
                 L253A R306Q R308L T368S E375Y A437G E466K 
                 GGGSGGGSGGGS 
               
               
                 D476H A484E E508R D510K K512Y E515Q P558A 
                 BtagV7 
               
               
                 D570S T571V 
                 GGGSGGGSGGGS 
               
               
                   
                 BtagV7 
               
               
                   
               
               
                 L142K Y224K E239G V250I L253A R306Q R308L 
                 His10 
               
               
                 E375Y A437G E466K D476H A484E E508R D510K 
                 GGGSGGGSGGGS 
               
               
                 K512Y E515Q P558A D570T T571A 
                 BtagV7 
               
               
                   
                 GGGSGGGSGGGS 
               
               
                   
                 BtagV7 
               
               
                   
               
               
                 K138C L142K Y224K E239G V250I L253A R306Q 
                 His10 
               
               
                 R308L E375Y A437G E466K D476H A484E E508R 
                 GGGSGGGSGGGS 
               
               
                 D510K K512Y E515Q D570S T571V 
                 BtagV7 
               
               
                   
                 GGGSGGGSGGGS 
               
               
                   
                 BtagV7 
               
               
                   
               
               
                 K138Q L142K Y224K E239G V2501 L253A R306Q 
                 His10 
               
               
                 R308L E375Y A437G E466K D476H A484E E508R 
                 GGGSGGGSGGGS 
               
               
                 D510K K512Y E515Q D570S T571V 
                 BtagV7 
               
               
                   
                 GGGSGGGSGGGS 
               
               
                   
                 BtagV7 
               
               
                   
               
               
                 K135Q L142K Y224K E239G V250I L253A R306Q 
                 His10 
               
               
                 R308L E375Y A437G E466K D476H A484E E508R 
                 GGGSGGGSGGGS 
               
               
                 D51OR K512Y E515Q K539E D570S T571V 
                 BtagV7 
               
               
                   
                 GGGSGGGSGGGS 
               
               
                   
                 BtagV7 
               
               
                   
               
               
                 K131E K135Q L142K Y224K E239G V250I L253A 
                 His10 
               
               
                 E375Y A437G D476H A484E E508R D510K K512Y 
                 GGGSGGGSGGGS 
               
               
                 E515Q D523R D570S T571V 
                 BtagV7 
               
               
                   
                 GGGSGGGSGGGS 
               
               
                   
                 BtagV7 
               
               
                   
               
               
                 L142K Y224K E239G V250I L253A R306Q R308L 
                 His10 
               
               
                 E375Y A437G E466K D476H A484E E508R D510K 
                 GGGSGGGSGGGS 
               
               
                 K512Y E515Q D570M 
                 BtagV7 
               
               
                   
                 GGGSGGGSGGGS 
               
               
                   
                 BtagV7 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 8 
               
             
            
               
                   
               
               
                 Exemplary mutations introduced into an M2Y 
               
               
                 DNA polymerase. Positions are identified 
               
               
                 relative to SEQ ID NO: 2. 
               
            
           
           
               
               
            
               
                   
                 C-terminal 
               
               
                   
                 region 
               
               
                 Mutations 
                 feature(s) 
               
               
                   
               
               
                 C103S E236G V247I L250A 5253A 
                 His10 
               
               
                 E372Y A434G A481E V503M E505R 
                 GGGSGGGSGGGS 
               
            
           
           
               
               
               
            
               
                 D507K K509Y E512Q 
                   
                 BtagV7 
               
               
                   
               
            
           
         
       
     
     The amino acid sequences of exemplary recombinant Φ29 and M2Y polymerases harboring the exemplary mutation combinations of Tables 7 and 8 are provided in Tables 9 and 10. Table 9 includes the polymerase portion of the molecule as well as the one or more exogenous features at the C-terminal region of the polymerase, while Table 10 includes the amino acid sequence of the polymerase portion only. 
     
       
         
           
               
             
               
                 TABLE 9 
               
             
            
               
                   
               
               
                 Amino acid sequences of exemplary recombinant Φ29 and M2Y  
               
               
                 polymerases including C-terminal exogenous features. Amino 
               
               
                 acid positions are identified relative to SEQ ID NO: 1 for 
               
               
                 recombinant Φ29 polymerases (denoted by “Phi29”) or 
               
               
                 relative to SEQ ID NO: 2 for recombinant M2Y polymerases 
               
               
                 (denoted by “M2”). 
               
            
           
           
               
               
            
               
                 SEQ ID NO 
                 Amino Acid Sequence 
               
               
                   
               
               
                 67 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.Y224K_E239G_V 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 250I_L253A_E375Y_A4 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 37G_A484E_E508R_D5 
                 LGYKGKRKIHTVIYDSLKKLPFPVKKIAKDFKLTVLK 
               
               
                 10K_K512Y_E515Q_D5 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 70M.G.His10.GGGSGG 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 GSGGGS.BtagV7 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                   
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                   
                 ELKEGYIPTIQIKRSRFYKGNEYLKSSGGEIADLWLSN 
               
               
                   
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVDP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKRVKGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDMTFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 68 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.A134S_Y224K_E2 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 39G_V250I_L253A_E37 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 5Y_A437G_A484E_548 
                 LGYKGKRKIHTVIYDSLKKLPFPVKKISKDFKLTVLK 
               
               
                 7A_E508R_D510K_K51 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 2Y_E515Q_I524S_F526 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 L_D570E.G.His10.GGG 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                 SGGGSGGGS.BtagV7 
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                   
                 ELKEGYIPTIQIKRSRFYKGNEYLKSSGGEIADLWLSN 
               
               
                   
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVDP 
               
               
                   
                 KKLGYWEHEATFKRAKYLRQKTYIQDIYMKRVKGY 
               
               
                   
                 LVQGSPDDYTDSKLSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDETFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 69 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.L142K_Y224K_E 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 239G_V250I_L253A_E3 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 75Y_A437G_D476H_A4 
                 LGYKGKRKIHTVIYDSLKKLPFPVKKIAKDFKLTVKK 
               
               
                 84E_E508R_D510K_K5 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 12Y_L513K_E515Q_D5 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 70E.G.His10.GGGSGGG 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                 SGGGS.BtagV7.GGGSG 
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                 GGSGGGS.BtagV7 
                 ELKEGYIPTIQIKRSRFYKGNEYLKSSGGEIADLWLSN 
               
               
                   
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVHP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKRVKGY 
               
               
                   
                 KVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDETFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHEGGGSG 
               
               
                   
                 GGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 70 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.L142K_Y224K_E 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 239G_V250I_L253A_R3 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 06Q_R308L_E375Y_A4 
                 LGYKGKRKIHTVIYDSLKKLPFPVKKIAKDFKLTVKK 
               
               
                 37G_D476H_A484E_E5 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 08R_D510K_K512Y_L5 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 13K_E515Q_D570E.G.H 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                 is10.GGGSGGGSGGGS. 
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                 BtagV7.GGGSGGGSGG 
                 ELKEGYIPTIQIKQSLFYKGNEYLKSSGGEIADLWLSN 
               
               
                 GS.BtagV7 
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVHP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKRVKGY 
               
               
                   
                 KVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDETFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHEGGGSG 
               
               
                   
                 GGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 71 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.L142K_Y224K_E 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 239G_V250I_L253A_R3 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 06Q_R308L_E375Y_A4 
                 LGYKGKRKIHTVIYDSLKKLPFPVKKIAKDFKLTVKK 
               
               
                 37G_E466K_D476H_A4 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 84E_E508R_D510K_K5 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 12Y_L513K_E515Q_D5 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                 70E.G.His10.GGGSGGG 
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                 SGGGS.BtagV7.GGGSG 
                 ELKEGYIPTIQIKQSLFYKGNEYLKS SGGEIADLWLSN 
               
               
                 GGSGGGS.BtagV7 
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTKIPDVIKDIVHP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKRVKGY 
               
               
                   
                 KVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDETFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHEGGGSG 
               
               
                   
                 GGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 72 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.L142K_Y224K_E 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 239G_V250I_L253A_R3 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 06Q_R308L_E375Y_A4 
                 LGYKGKRKIHTVIYDSLKKLPFPVKKIAKDFKLTVKK 
               
               
                 37G_E466K_D476H_A4 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 84E_E508R_D510K_K5 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 12Y_E515Q_D570E.G.H 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                 is10.GGGSGGGSGGGS. 
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                 BtagV7.GGGSGGGSGG 
                 ELKEGYIPTIQIKQSLFYKGNEYLKSSGGEIADLWLSN 
               
               
                 GS.BtagV7 
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTKIPDVIKDIVHP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKRVKGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDETFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHEGGGSG 
               
               
                   
                 GGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 73 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.L142K_Y224K_E 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 239G_V250I_L253A_E3 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 75Y_A437G_E466K_D4 
                 LGYKGKRKIHTVIYDSLKKLPFPVKKIAKDFKLTVKK 
               
               
                 76H_A484E_E508R_D5 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 10K_K512Y_E515Q_D5 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 70E.G.His10.GGGSGGG 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                 SGGGS.BtagV7.GGGSG 
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                 GGSGGGS.BtagV7 
                 ELKEGYIPTIQIKRSRFYKGNEYLKSSGGEIADLWLSN 
               
               
                   
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTKIPDVIKDIVHP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKRVKGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDETFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHEGGGSG 
               
               
                   
                 GGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 74 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.L142K_Y224K_E 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 239G_V250I L253A E3 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 75Y_M429A_A437G_A 
                 LGYKGKRKIHTVIYDSLKKLPFPVKKIAKDFKLTVKK 
               
               
                 484E_E508R_D510K_K 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 512Y_E515Q_D570E.G. 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 His10.GGGS GGGSGGG 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                 S.BtagV7.GGGSGGGSG 
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                 GGS.BtagV7 
                 ELKEGYIPTIQIKRSRFYKGNEYLKSSGGEIADLWLSN 
               
               
                   
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPAGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVDP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKRVKGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDETFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHEGGSG 
               
               
                   
                 GGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 75 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.A134S_L142K_Y2 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 24K_E239G V250I L25 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 3A E375Y_A437G_A48 
                 LGYKGKRKIHTVIYDSLKKLPFPVKKISKDFKLTVKK 
               
               
                 4E_S487A_E508R_D510 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 K_K512Y_E515Q_1524S_ 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 F526L_D570E.G.His10. 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                 GGGSGGGSGGGS.B tag 
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                 V7 
                 ELKEGYIPTIQIKRSRFYKGNEYLKSSGGEIADLWLSN 
               
               
                   
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVDP 
               
               
                   
                 KKLGYWEHEATFKRAKYLRQKTYIQDIYMKRVKGY 
               
               
                   
                 LVQGSPDDYTDSKLSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDETFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 76 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.Y224K_E239G V 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 250I_L253A_E375Y_A4 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 37G_A484E_S487A_E5 
                 LGYKGKRKIHTVIYDSLKKLPFPVKKIAKDFKLTVLK 
               
               
                 08R_D510K_K512Y_E5 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 15Q_I524S_F526L_D57 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 0M.G.His10.GGGS GGG 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                 SGGGS.BtagV7 
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                   
                 ELKEGYIPTIQIKRSRFYKGNEYLKSSGGEIADLWLSN 
               
               
                   
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVDP 
               
               
                   
                 KKLGYWEHEATFKRAKYLRQKTYIQDIYMKRVKGY 
               
               
                   
                 LVQGSPDDYTDSKLSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDMTFTIKGHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 77 
                 MSRKMFSCDFETTTKLDDCRVWAYGYMEIGNLDNY 
               
               
                 M2.C103S_E236G_V247 
                 KIGNSLDEFMQWVMEIQADLYFHNLKFDGAFIVNWL 
               
               
                 I_L250A_S253A_E372Y_ 
                 EQHGFKWSNEGLPNTYNTIISKMGQWYMIDISFGYK 
               
               
                 A434G_A481E_V503M_ 
                 GKRKLHTVIYDSLKKLPFPVKKIAKDFQLPLLKGDID 
               
               
                 E505R_D507K_K509Y_ 
                 YHTERPVGHEITPEEYEYIKNDIEIIARALDIQFKQGLD 
               
               
                 E512Q.G.His10.GGGS 
                 RMTAGSDSLKGFKDILSTKKFNKVFPKLSLPMDKEIR 
               
               
                 GGGSGGGS.BtagV7 
                 KAYRGGFTWLNDKYKGKEIGEGMVFDINSAYPAQM 
               
               
                   
                 YSRPLPYGAPIVFQGKYEKDEQYPLYIQRIRFEFELKE 
               
               
                   
                 GYIPTIQIKKNPFFKGNEYLKNSGVEPVELYLTNVDL 
               
               
                   
                 ELIQEHYELYNVEYIDGFKFREKTGLFKDFIDKWTYV 
               
               
                   
                 KTHEYGAKKQLAKLMLNSLYGKFASNPDVTGKVPY 
               
               
                   
                 LKDDGSLGFRVGDEEYKDPVYTPMGVFITAWGRFTT 
               
               
                   
                 ITAAQACYDRIIYCDTDSIHLTGTEVPEIIKDIVDPKKL 
               
               
                   
                 GYWEHESTFKRAKYLRQKTYIQDIYMKRVKGYLKQ 
               
               
                   
                 CSPDEATTTKFSVKCAGMTDTIKKKVTFDNFAVGFSS 
               
               
                   
                 MGKPKPVQVNGGVVLVDSVFTIKGHHHHHHHHHH 
               
               
                   
                 GGGSGGGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 78 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.L142K_Y224K_D 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLK14DGAFI 
               
               
                 235E_E239G_V250A L 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 253H_E375Y_A437G_A 
                 LGYKGKRKIHTVIYDSLKKLPFPVKKIAKDFKLTVKK 
               
               
                 484E_E508R_D510K_K 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 512Y_E515Q_D570E.Hi 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 s10.GGGSGGGSGGGS. 
                 KEVRKAYRGGFTWLNERFKGKEIGEGMVFDANSHY 
               
               
                 BtagV7 
                 PAQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCE 
               
               
                   
                 FELKEGYIPTIQIKRSRFYKGNEYLKSSGGEIADLWLS 
               
               
                   
                 NVDLELMKEHYDLYNVEYISGLKFKATTGLFKDFID 
               
               
                   
                 KWTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTG 
               
               
                   
                 KVPYLKENGALGFRLGEEETKDPVYTPMGVFITAWG 
               
               
                   
                 RYTTITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVD 
               
               
                   
                 PKKLGYWEHESTFKRAKYLRQKTYIQDIYMKRVKG 
               
               
                   
                 YLVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFK 
               
               
                   
                 VGFSRKMKPKPVQVPGGVVLVDETFTIKGHHHHHH 
               
               
                   
                 HHHHGGGSGGGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 79 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.Y224K_E239G V 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 2501_L253A_E375Y_A4 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 37G_A484E_E508R_D5 
                 LGYKGKRKIHTVIYDSLKKLPFPVKKIAKDFKLTVLK 
               
               
                 10K_K512Y_E515Q.His 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 10.GGGSGGGSGGGS.B 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 tagV7 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                   
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                   
                 ELKEGYIPTIQIKRSRFYKGNEYLKSSGGEIADLWLSN 
               
               
                   
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVDP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKRVKGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDDTFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 80 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.V141K_L142K_Y 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKIDGAFI 
               
               
                 224K_E239G_V250I_L2 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 53A_E375Y_A437G_A4 
                 LGYKGKRKIHTVIYDSLKKLPFPVKKIAKDFKLTKKK 
               
               
                 84E_E508R_D510K_K5 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 12Y_E515Q.His10.GGG 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 SGGGSGGGS.BtagV7 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                   
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                   
                 ELKEGYIPTIQIKRSRFYKGNEYLKSSGGEIADLWLSN 
               
               
                   
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVDP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKRVKGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDDTFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 95 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.K135Q_L142K_Y 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 224K_E239G_V250I_L2 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 53A_R306Q_R308L_E3 
                 LGYKGKRKIHTVIYDSLKKLPFPVKKIAQDFKLTVKK 
               
               
                 75Y_A437G_E466K_D4 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 76H_A484E_E508R_D5 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 10R_K512Y_E515Q_D5 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                 70S_T571V.G.His10co.G 
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                 GGSGGGSGGGS.BtagV 
                 ELKEGYIPTIQIKQSLFYKGNEYLKSSGGEIADLWLSN 
               
               
                 7.GGGSGGGSGGGS.Bt 
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                 agV7 
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTKIPDVIKDIVHP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKRVRGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDSVFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHEGGGSG 
               
               
                   
                 GGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 96 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.K131E_K135Q_L 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 142K_Y224K_E239G_V 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 250I_L253A_E375Y_A4 
                 LGYKGKRKIHTVIYDSLKKLPFPVEKIAQDFKLTVKK 
               
               
                 37G_A484E_E508R_D5 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 10R_K512Y_E515Q_D5 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 23R_P558A_D570S_T57 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                 1V.G.His10.GGGS GGG 
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                 SGGGS.BtagV7.GGGSG 
                 ELKEGYIPTIQIKRSRFYKGNEYLKSSGGEIADLWLSN 
               
               
                 GGSGGGS.BtagV7 
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVDP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKRVRGY 
               
               
                   
                 LVQGSPDDYTRIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKAVQVPGGVVLVDSVFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHEGGGSG 
               
               
                   
                 GGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 97 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.A49E_C106S_K11 
                 HSEYKIGNSLDEFMEWVLKVQADLYFHNLKFDGAFI 
               
               
                 4R_K131E_K135Q_L14 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIS 
               
               
                 2K_Y224K_E239G_V25 
                 LGYKGKRRIHTVIYDSLKKLPFPVEKIAQDFKLTVKK 
               
               
                 0I_L253A_Y369E_E375 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 Y_A437G_D476H_A484 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 E_E508R_D510K_K512 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                 Y_E515Q_D523R_D570 
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                 S_T571V.G.His10.GGG 
                 ELKEGYIPTIQIKRSRFYKGNEYLKSSGGEIADLWLSN 
               
               
                 SGGGSGGGS.BtagV7.G 
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                 GGSGGGSGGGS.BtagV 
                 WTEIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                 7 
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVHP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKRVKGY 
               
               
                   
                 LVQGSPDDYTRIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDSVFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHEGGGSG 
               
               
                   
                 GGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 98 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.K135Q_K138Q_L 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 142K_Y224K_E239G_V 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 250I_L253A_R306Q_R3 
                 LGYKGKRKIHTVIYDSLKKLPFPVKKIAQDFQLTVKK 
               
               
                 08L_E375Y_A437G_E4 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 66K_D476H_A484E_E5 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 08R_D510K_K512Y_E5 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                 15Q_I524T_P558A_D57 
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                 0S_T571V.G.His10.GGG 
                 ELKEGYIPTIQIKQSLFYKGNEYLKSSGGEIADLWLSN 
               
               
                 SGGGSGGGS.BtagV7.G 
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                 GGSGGGSGGGS.BtagV 
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                 7 
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTKIPDVIKDIVHP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKRVKGY 
               
               
                   
                 LVQGSPDDYTDTKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKAVQVPGGVVLVDSVFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHEGGGSG 
               
               
                   
                 GGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 99 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.K135Q_K138Q_L 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 142K_Y224K_E239G_V 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 250I_L253A_R306Q_R3 
                 LGYKGKRKIHTVIYDSLKKLPFPVKKIAQDFQLTVKK 
               
               
                 08L_E375Y_A437G_E4 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 66K_V475I_D476H_A4 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 84E_E508R_D510K_K5 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                 12Y_E515Q_I524T_P55 
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                 8A_D570S_T571V.G.Hi 
                 ELKEGYIPTIQIKQSLFYKGNEYLKSSGGEIADLWLSN 
               
               
                 s10.GGGSGGGSGGGS. 
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                 BtagV7.GGGS GGGSGG 
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                 GS.BtagV7 
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTKIPDVIKDIIHP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKRVKGY 
               
               
                   
                 LVQGSPDDYTDTKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKAVQVPGGVVLVDSVFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHEGGGSG 
               
               
                   
                 GGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 100 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.K135Q_K138Q_L 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 142K_Y224K_E239G_V 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 250I_L253A_R306Q_R3 
                 LGYKGKRKIHTVIYDSLKKLPFPVKKIAQDFQLTVKK 
               
               
                 08L_T368S_E375Y_A43 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 7G_E466K_D476H_A48 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 4E_E508R_D510K_K51 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                 2Y_E515Q_I524T_P558 
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                 A_D570S_T571V.G.His 
                 ELKEGYIPTIQIKQSLFYKGNEYLKSSGGEIADLWLSN 
               
               
                 10.GGGSGGGSGGGS.B 
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                 tagV7.GGGSGGGSGGG 
                 WSYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                 S.BtagV7 
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTKIPDVIKDIVHP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKRVKGY 
               
               
                   
                 LVQGSPDDYTDTKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKAVQVPGGVVLVDSVFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHEGGGSG 
               
               
                   
                 GGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 101 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.K135Q_K138Q_L 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 142K_Y224K_E239G_V 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 250I_L253A_R306Q_R3 
                 LGYKGKRKIHTVIYDSLKKLPFPVKKIAQDFQLTVKK 
               
               
                 08L_T368S_E375Y_A43 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 7G_E466K_V475I_D476 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 H_A484E_E508R_D510 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                 K_K512Y_E515Q_P558 
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                 A_D570S_T571V.G.His 
                 ELKEGYIPTIQIKQSLFYKGNEYLKSSGGEIADLWLSN 
               
               
                 10.GGGSGGGSGGGS.B 
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                 tagV7.GGGSGGGSGGG 
                 WSYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                 S.BtagV7 
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTKIPDVIKDIIHP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKRVKGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKAVQVPGGVVLVDSVFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHEGGGSG 
               
               
                   
                 GGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 102 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.L44A_K135Q_K1 
                 HSEYKIGNSADEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 38Q_L142K_Y224K_E2 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 39G_V250I_L253A_R30 
                 LGYKGKRKIHTVIYDSLKKLPFPVKKIAQDFQLTVKK 
               
               
                 6Q_R308L_E375Y_A43 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 7G_E466K_D476H_A48 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 4E_S487A_E508R_D510 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                 K_K512Y_E515Q_P558 
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                 A_D570S_T571V.G.His 
                 ELKEGYIPTIQIKQSLFYKGNEYLKSSGGEIADLWLSN 
               
               
                 10.GGGSGGGSGGGS .B 
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                 tagV7.GGGSGGGSGGG 
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                 S.BtagV7 
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTKIPDVIKDIVHP 
               
               
                   
                 KKLGYWEHEATFKRAKYLRQKTYIQDIYMKRVKGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKAVQVPGGVVLVDSVFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHEGGGSG 
               
               
                   
                 GGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 103 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.K135Q_L142K_Y 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 224K_E239G_V250I_L2 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 53A_R306Q_R308L_T3 
                 LGYKGKRKIHTVIYDSLKKLPFPVKKIAQDFKLTVKK 
               
               
                 68S_E375Y_A437G_E4 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 66K_D476H_A484E_E5 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 08R_D510R_K512Y_E5 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                 15Q_P558A_D570S_T57 
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                 1V.G.His10.GGGSGGG 
                 ELKEGYIPTIQIKQSLFYKGNEYLKS SGGEIADLWLSN 
               
               
                 SGGGS.BtagV7.GGGSG 
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                 GGSGGGS.BtagV7 
                 WSYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTKIPDVIKDIVHP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKRVRGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKAVQVPGGVVLVDSVFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHEGGGSG 
               
               
                   
                 GGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 104 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.A49E_C106S_K11 
                 HSEYKIGNSLDEFMEWVLKVQADLYFHNLKFDGAFI 
               
               
                 4R_K135Q_L142K_Y22 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIS 
               
               
                 4K_E239G_V250I_L253 
                 LGYKGKRRIHTVIYDSLKKLPFPVKKIAQDFKLTVKK 
               
               
                 A_R306Q_R308L_E375 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 Y_A437G_E466K_D476 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 H_A484E_E508R_D510 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                 R_K512Y_E515Q_K536 
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                 Q_K539Q_D570S_T571 
                 ELKEGYIPTIQIKQSLFYKGNEYLKS SGGEIADLWLSN 
               
               
                 V.G.His10.GGGSGGGS 
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                 GGGS.BtagV7.GGGSG 
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                 GGSGGGS.BtagV7 
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTKIPDVIKDIVHP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKRVRGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDQIKQEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDSVFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHEGGGSG 
               
               
                   
                 GGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 105 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.L44A_K135Q_K1 
                 HSEYKIGNSADEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 38Q_L142K_Y224K_E2 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 39G_V250I_L253A_R30 
                 LGYKGKRKIHTVIYDSLKKLPFPVKKIAQDFQLTVKK 
               
               
                 6Q_R308L_T3685_E375 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 Y_A437G_E466K_D476 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 H_A484E_E508R_D510 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                 K_K512Y_E515Q_P558 
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                 A_D570S_T571V.G.His 
                 ELKEGYIPTIQIKQSLFYKGNEYLKS SGGEIADLWLSN 
               
               
                 10.GGGSGGGSGGGS.B 
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                 tagV7.GGGSGGGSGGG 
                 WSYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                 S.BtagV7 
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTKIPDVIKDIVHP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKRVKGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKAVQVPGGVVLVDSVFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHEGGGSG 
               
               
                   
                 GGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 106 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.L142K_Y224K_E 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 239G_V250I_L253A_R3 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 06Q_R308L_E375Y_A4 
                 LGYKGKRKIHTVIYDSLKKLPFPVKKIAKDFKLTVKK 
               
               
                 37G_E466K_D476H_A4 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 84E_E508R_D510K_K5 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 12Y_E515Q_P558A_D5 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                 70T_T571A.G.His10.GG 
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                 GSGGGSGGGS.BtagV7. 
                 ELKEGYIPTIQIKQSLFYKGNEYLKSSGGEIADLWLSN 
               
               
                 GGGSGGGSGGGS.Btag 
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                 V7 
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTKIPDVIKDIVHP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKRVKGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKAVQVPGGVVLVDTAFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHEGGGSG 
               
               
                   
                 GGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 107 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.K138C_L142K_Y 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 224K_E239G_V250I_L2 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 53A_R306Q_R308L_E3 
                 LGYKGKRKIHTVIYDSLKKLPFPVKKIAKDFCLTVKK 
               
               
                 75Y_A437G_E466K_D4 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 76H_A484E_E508R_D5 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 10K_K512Y_E515Q_D5 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                 705_T571V.G.His10.GG 
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                 GSGGGSGGGS.BtagV7. 
                 ELKEGYIPTIQIKQSLFYKGNEYLKSSGGEIADLWLSN 
               
               
                 GGGSGGGSGGGS.Btag 
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                 V7 
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTKIPDVIKDIVHP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKRVKGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDSVFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHEGGGSG 
               
               
                   
                 GGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 108 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.K138Q_L142K_Y 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 224K_E239G_V250I_L2 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 53A_R306Q_R308L_E3 
                 LGYKGKRKIHTVIYDSLKKLPFPVKKIAKDFQLTVKK 
               
               
                 75Y_A437G_E466K_D4 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 76H_A484E_E508R_D5 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 10K_K512Y_E515Q_D5 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                 70S_T571V.G.His10.GG 
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                 GSGGGSGGGS.BtagV7. 
                 ELKEGYIPTIQIKQSLFYKGNEYLKS SGGEIADLWLSN 
               
               
                 GGGSGGGSGGGS.Btag 
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                 V7 
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTKIPDVIKDIVHP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKRVKGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDSVFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHEGGGSG 
               
               
                   
                 GGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 109 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.K135Q_L142K_Y 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 224K_E239G_V250I_L2 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 53A_R306Q_R308L_E3 
                 LGYKGKRKIHTVIYDSLKKLPFPVKKIAQDFKLTVKK 
               
               
                 75Y_A437G_E466K_D4 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 76H_A484E_E508R_D5 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 10R_K512Y_E515Q_K5 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                 39E_D570S_T571V.G.H 
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                 is10.GGGSGGGSGGGS. 
                 ELKEGYIPTIQIKQSLFYKGNEYLKSSGGEIADLWLSN 
               
               
                 BtagV7.GGGSGGGSGG 
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                 GS.BtagV7 
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTKIPDVIKDIVHP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKRVRGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDKIKEEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDSVFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHEGGGSG 
               
               
                   
                 GGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 110 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.K131E_K135Q_L 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 142K_Y224K_E239G_V 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 250I_L253A_E375Y_A4 
                 LGYKGKRKIHTVIYDSLKKLPFPVEKIAQDFKLTVKK 
               
               
                 37G_D476H_A484E_E5 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 08R_D510K_K512Y_E5 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 15Q_D523R_D570S_T5 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                 71V.G.His10.GGGSGG 
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                 GSGGGS.BtagV7.GGGS 
                 ELKEGYIPTIQIKRSRFYKGNEYLKSSGGEIADLWLSN 
               
               
                 GGGSGGGS.BtagV7 
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTEIPDVIKDIVHP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKRVKGY 
               
               
                   
                 LVQGSPDDYTRIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDSVFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHEGGGSG 
               
               
                   
                 GGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
               
                 111 
                 MKHMPRKMYSCDFETTTKVEDCRVWAYGYMNIED 
               
               
                 Phi29.L142K_Y224K_E 
                 HSEYKIGNSLDEFMAWVLKVQADLYFHNLKFDGAFI 
               
               
                 239G_V250I_L253A_R3 
                 INWLERNGFKWSADGLPNTYNTIISRMGQWYMIDIC 
               
               
                 06Q_R308L_E375Y_A4 
                 LGYKGKRKIHTVIYDSLKKLPFPVKKIAKDFKLTVKK 
               
               
                 37G_E466K_D476H_A4 
                 GDIDYHKERPVGYKITPEEYAYIKNDIQIIAEALLIQFK 
               
               
                 84E_E508R_D510K_K5 
                 QGLDRMTAGSDSLKGFKDIITTKKFKKVFPTLSLGLD 
               
               
                 12Y_E515Q_D570M.G. 
                 KEVRKAYRGGFTWLNDRFKGKEIGEGMVFDINSAYP 
               
               
                 His10.GGGSGGGSGGG 
                 AQMYSRLLPYGEPIVFEGKYVWDEDYPLHIQHIRCEF 
               
               
                 S.BtagV7.GGGSGGGSG 
                 ELKEGYIPTIQIKQSLFYKGNEYLKSSGGEIADLWLSN 
               
               
                 GGS.BtagV7 
                 VDLELMKEHYDLYNVEYISGLKFKATTGLFKDFIDK 
               
               
                   
                 WTYIKTTSYGAIKQLAKLMLNSLYGKFASNPDVTGK 
               
               
                   
                 VPYLKENGALGFRLGEEETKDPVYTPMGVFITAWGR 
               
               
                   
                 YTTITAAQACYDRIIYCDTDSIHLTGTKIPDVIKDIVHP 
               
               
                   
                 KKLGYWEHESTFKRAKYLRQKTYIQDIYMKRVKGY 
               
               
                   
                 LVQGSPDDYTDIKFSVKCAGMTDKIKKEVTFENFKV 
               
               
                   
                 GFSRKMKPKPVQVPGGVVLVDMTFTIKGHHHHHHH 
               
               
                   
                 HHHGGGSGGGSGGGSGLNDFFEAQKIEWHEGGGSG 
               
               
                   
                 GGSGGGSGLNDFFEAQKIEWHE 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 10 
               
             
            
               
                   
               
               
                 Amino acid sequences of exemplary recombinant 
               
               
                 Φ29 and M2Y polymerases. Amino acid 
               
               
                 positions are identified relative to SEQ 
               
               
                 ID NO: 1 for recombinant Φ29 polymerases 
               
               
                 (denoted by “Phi29”) or relative to 
               
               
                 SEQ ID NO: 2 for recombinant M2Y 
               
               
                 polymerases (denoted by “M2”). 
               
            
           
           
               
               
               
            
               
                   
                 SEQ ID NO 
                 Amino Acid Sequence 
               
               
                   
               
               
                   
                 81 
                 MKHMPRKMYSCDFETTTKVE 
               
               
                   
                 Phi29.Y224K_E239G_V 
                 DCRVWAYGYMNIEDHSEYKI 
               
               
                   
                 250I_L253A_E375Y_A4 
                 GNSLDEFMAWVLKVQADLYF 
               
               
                   
                 37G_A484E_E508R_D5 
                 HNLKFDGAFIINWLERNGFK 
               
               
                   
                 10K_K512Y_E515Q_D5 
                 WSADGLPNTYNTIISRMGQW 
               
               
                   
                 70M 
                 YMIDICLGYKGKRKIHTVIY 
               
               
                   
                   
                 DSLKKLPFPVKKIAKDFKLT 
               
               
                   
                   
                 VLKGDIDYHKERPVGYKITP 
               
               
                   
                   
                 EEYAYIKNDIQIIAEALLIQ 
               
               
                   
                   
                 FKQGLDRMTAGSDSLKGFKD 
               
               
                   
                   
                 IITTKKFKKVFPTLSLGLDK 
               
               
                   
                   
                 EVRKAYRGGFTWLNDRFKGK 
               
               
                   
                   
                 EIGEGMVFDINSAYPAQMYS 
               
               
                   
                   
                 RLLPYGEPIVFEGKYVWDED 
               
               
                   
                   
                 YPLHIQHIRCEFELKEGYIP 
               
               
                   
                   
                 TIQIKRSRFYKGNEYLKSSG 
               
               
                   
                   
                 GEIADLWLSNVDLELMKEHY 
               
               
                   
                   
                 DLYNVEYISGLKFKATTGLF 
               
               
                   
                   
                 KDFIDKWTYIKTTSYGAIKQ 
               
               
                   
                   
                 LAKLMLNSLYGKFASNPDVT 
               
               
                   
                   
                 GKVPYLKENGALGFRLGEEE 
               
               
                   
                   
                 TKDPVYTPMGVFITAWGRYT 
               
               
                   
                   
                 TITAAQACYDRIIYCDTDSI 
               
               
                   
                   
                 HLTGTEIPDVIKDIVDPKKL 
               
               
                   
                   
                 GYWEHESTFKRAKYLRQKTY 
               
               
                   
                   
                 IQDIYMKRVKGYLVQGSPDD 
               
               
                   
                   
                 YTDIKFSVKCAGMTDKIKKE 
               
               
                   
                   
                 VTFENFKVGFSRKMKPKPVQ 
               
               
                   
                   
                 VPGGVVLVDMTFTIK 
               
               
                   
               
               
                   
                 82 
                 MKHMPRKMYSCDFETTTKVE 
               
               
                   
                 Phi29.A134S_Y224K_E2 
                 DCRVWAYGYMNIEDHSEYKI 
               
               
                   
                 39G_V250I_L253A_E37 
                 GNSLDEFMAWVLKVQADLYF 
               
               
                   
                 5Y_A437G_A484E_S48 
                 HNLKFDGAFIINWLERNGFK 
               
               
                   
                 7A_E508R_D510K_K51 
                 WSADGLPNTYNTIISRMGQW 
               
               
                   
                 2Y_E515Q_I524S_ 
                 YMIDICLGYKGKRKIHTVIY 
               
               
                   
                 F526L_D570E 
                 DSLKKLPFPVKKISKDFKLT 
               
               
                   
                   
                 VLKGDIDYHKERPVGYKITP 
               
               
                   
                   
                 EEYAYIKNDIQIIAEALLIQ 
               
               
                   
                   
                 FKQGLDRMTAGSDSLKGFKD 
               
               
                   
                   
                 IITTKKFKKVFPTLSLGLDK 
               
               
                   
                   
                 EVRKAYRGGFTWLNDRFKGK 
               
               
                   
                   
                 EIGEGMVFDINSAYPAQMYS 
               
               
                   
                   
                 RLLPYGEPIVFEGKYVWDED 
               
               
                   
                   
                 YPLHIQHIRCEF 
               
               
                   
                   
                 ELKEGYIPTIQIKRSRFYKG 
               
               
                   
                   
                 NEYLKSSGGEIADLWLSNVD 
               
               
                   
                   
                 LELMKEHYDLYNVEYISGLK 
               
               
                   
                   
                 FKATTGLFKDFIDKWTYIKT 
               
               
                   
                   
                 TSYGAIKQLAKLMLNSLYGK 
               
               
                   
                   
                 FASNPDVTGKVPYLKENGAL 
               
               
                   
                   
                 GFRLGEEETKDPVYTPMGVF 
               
               
                   
                   
                 ITAWGRYTTITAAQACYDRH 
               
               
                   
                   
                 YCDTDSIHLTGTEIPDVIKD 
               
               
                   
                   
                 IVDPKKLGYWEHEATFKRAK 
               
               
                   
                   
                 YLRQKTYIQDIYMKRVKGYL 
               
               
                   
                   
                 VQGSPDDYTDSKLSVKCAGM 
               
               
                   
                   
                 TDKIKKEVTFENFKVGFSRK 
               
               
                   
                   
                 MKPKPVQVPGGVVLVDETFT 
               
               
                   
                   
                 IK 
               
               
                   
               
               
                   
                 83 
                 MKHMPRKMYSCDFETTTKVE 
               
               
                   
                 Phi29.L142K_Y224K_E 
                 DCRVWAYGYMNIEDHSEYKI 
               
               
                   
                 239G_V250I_L253A_E3 
                 GNSLDEFMAWVLKVQADLYF 
               
               
                   
                 75Y_A437G_D476H_A4 
                 HNLKFDGAFIINWLERNGFK 
               
               
                   
                 84E_E508R_D510K_K5 
                 WSADGLPNTYNTIISRMGQW 
               
               
                   
                 12Y_L513K_E515Q_ 
                 YMIDICLGYKGKRKIHTVIY 
               
               
                   
                 D570E 
                 DSLKKLPFPVKKIAKDFKLT 
               
               
                   
                   
                 VKKGDIDYHKERPVGYKITP 
               
               
                   
                   
                 EEYAYIKNDIQIIAEALLIQ 
               
               
                   
                   
                 FKQGLDRMTAGSDSLKGFKD 
               
               
                   
                   
                 IITTKKFKKVFPTLSLGLDK 
               
               
                   
                   
                 EVRKAYRGGFTWLNDRFKGK 
               
               
                   
                   
                 EIGEGMVFDINSAYPAQMYS 
               
               
                   
                   
                 RLLPYGEPIVFEGKYVWDED 
               
               
                   
                   
                 YPLHIQHIRCEFELKEGYIP 
               
               
                   
                   
                 TIQIKRSRFYKGNEYLKSSG 
               
               
                   
                   
                 GEIADLWLSNVDLELMKEHY 
               
               
                   
                   
                 DLYNVEYISGLKFKATTGLF 
               
               
                   
                   
                 KDFIDKWTYIKTTSYGAIKQ 
               
               
                   
                   
                 LAKLMLNSLYGKFASNPDVT 
               
               
                   
                   
                 GKVPYLKENGALGFRLGEEE 
               
               
                   
                   
                 TKDPVYTPMGVFITAWGRYT 
               
               
                   
                   
                 TITAAQACYDRIIYCDTDSI 
               
               
                   
                   
                 HLTGTEIPDVIKDIVHPKKL 
               
               
                   
                   
                 GYWEHESTFKRAKYLRQKTY 
               
               
                   
                   
                 IQDIYMKRVKGYKVQGSPDD 
               
               
                   
                   
                 YTDIKFSVKCAGMTDKIKKE 
               
               
                   
                   
                 VTFENFKVGFSRKMKPKPVQ 
               
               
                   
                   
                 VPGGVVLVDETFTIK 
               
               
                   
               
               
                   
                 84 
                 MKHMPRKMYSCDFETTTKVE 
               
               
                   
                 Phi29.L142K_Y224K_E 
                 DCRVWAYGYMNIEDHSEYKI 
               
               
                   
                 239G_V250I_L253A_R3 
                 GNSLDEFMAWVLKVQADLYF 
               
               
                   
                 06Q_R308L_E375Y_A4 
                 HNLKFDGAFIINWLERNGFK 
               
               
                   
                 37G_D476H_A484E_E5 
                 WSADGLPNTYNTIISRMGQW 
               
               
                   
                 08R_D510K_K512Y_L5 
                 YMIDICLGYKGKRKIHTVIY 
               
               
                   
                 13K_E515Q_D570E 
                 DSLKKLPFPVKKIAKDFKLT 
               
               
                   
                   
                 VKKGDIDYHKERPVGYKITP 
               
               
                   
                   
                 EEYAYIKNDIQIIAEALLIQ 
               
               
                   
                   
                 FKQGLDRMTAGSDSLKGFKD 
               
               
                   
                   
                 IITTKKFKKVFPTLSLGLDK 
               
               
                   
                   
                 EVRKAYRGGFTWLNDRFKGK 
               
               
                   
                   
                 EIGEGMVFDINSAYPAQMYS 
               
               
                   
                   
                 RLLPYGEPIVFEGKYVWDED 
               
               
                   
                   
                 YPLHIQHIRCEFELKEGYIP 
               
               
                   
                   
                 TIQIKQSLFYKGNEYLKSSG 
               
               
                   
                   
                 GEIADLWLSNVDLELMKEHY 
               
               
                   
                   
                 DLYNVEYISGLKFKATTGLF 
               
               
                   
                   
                 KDFIDKWTYIKTTSYGAIKQ 
               
               
                   
                   
                 LAKLMLNSLYGKFASNPDVT 
               
               
                   
                   
                 GKVPYLKENGALGFRLGEEE 
               
               
                   
                   
                 TKDPVYTPMGVFITAWGRYT 
               
               
                   
                   
                 TITAAQACYDRIIYCDTDSI 
               
               
                   
                   
                 HLTGTEIPDVIKDIVHPKKL 
               
               
                   
                   
                 GYWEHESTFKRAKYLRQKTY 
               
               
                   
                   
                 IQDIYMKRVKGYKVQGSPDD 
               
               
                   
                   
                 YTDIKFSVKCAGMTDKIKKE 
               
               
                   
                   
                 VTFENFKVGFSRKMKPKPVQ 
               
               
                   
                   
                 VPGGVVLVDETFTIK 
               
               
                   
               
               
                   
                 85 
                 MKHMPRKMYSCDFETTTKVE 
               
               
                   
                 Phi29.L142K_Y224K_E 
                 DCRVWAYGYMNIEDHSEYKI 
               
               
                   
                 239G_V250I_L253A_R3 
                 GNSLDEFMAWVLKVQADLYF 
               
               
                   
                 06Q_R308L_E375Y_A4 
                 HNLKFDGAFIINWLERNGFK 
               
               
                   
                 37G_E466K_D476H_A4 
                 WSADGLPNTYNTIISRMGQW 
               
               
                   
                 84E_E508R_D510K_K5 
                 YMIDICLGYKGKRKIHTVIY 
               
               
                   
                 12Y_L513K_E515Q_D5 
                 DSLKKLPFPVKKIAKDFKLT 
               
               
                   
                 70E 
                 VKKGDIDYHKERPVGYKITP 
               
               
                   
                   
                 EEYAYIKNDIQIIAEALLIQ 
               
               
                   
                   
                 FKQGLDRMTAGSDSLKGFKD 
               
               
                   
                   
                 IITTKKFKKVFPTLSLGLDK 
               
               
                   
                   
                 EVRKAYRGGFTWLNDRFKGK 
               
               
                   
                   
                 EIGEGMVFDINSAYPAQMYS 
               
               
                   
                   
                 RLLPYGEPIVFEGKYVWDED 
               
               
                   
                   
                 YPLHIQHIRCEFELKEGYIP 
               
               
                   
                   
                 TIQIKQSLFYKGNEYLKSSG 
               
               
                   
                   
                 GEIADLWLSNVDLELMKEHY 
               
               
                   
                   
                 DLYNVEYISGLKFKATTGLF 
               
               
                   
                   
                 KDFIDKWTYIKTTSYGAIKQ 
               
               
                   
                   
                 LAKLMLNSLYGKFASNPDVT 
               
               
                   
                   
                 GK 
               
               
                   
                   
                 VPYLKENGALGFRLGEEETK 
               
               
                   
                   
                 DPVYTPMGVFITAWGRYTTI 
               
               
                   
                   
                 TAAQACYDRIIYCDTDSIHL 
               
               
                   
                   
                 TGTKIPDVIKDIVHPKKLGY 
               
               
                   
                   
                 WEHESTFKRAKYLRQKTYIQ 
               
               
                   
                   
                 DIYMKRVKGYKVQGSPDDYT 
               
               
                   
                   
                 DIKFSVKCAGMTDKIKKEVT 
               
               
                   
                   
                 FENFKVGFSRKMKPKPVQVP 
               
               
                   
                   
                 GGVVLVDETFTIK 
               
               
                   
               
               
                   
                 86 
                 MKHMPRKMYSCDFETTTKVE 
               
               
                   
                 Phi29.L142K_Y224K_E 
                 DCRVWAYGYMNIEDHSEYKI 
               
               
                   
                 239G_V250I_L253A_R3 
                 GNSLDEFMAWVLKVQADLYF 
               
               
                   
                 06Q_R308L_E375Y_A4 
                 HNLKFDGAFIINWLERNGFK 
               
               
                   
                 37G_E466K_D476H_A4 
                 WSADGLPNTYNTIISRMGQW 
               
               
                   
                 84E_E508R_D510K_K5 
                 YMIDICLGYKGKRKIHTVIY 
               
               
                   
                 12Y_E515Q_D570E 
                 DSLKKLPFPVKKIAKDFKLT 
               
               
                   
                   
                 VKKGDIDYHKERPVGYKITP 
               
               
                   
                   
                 EEYAYIKNDIQIIAEALLIQ 
               
               
                   
                   
                 FKQGLDRMTAGSDSLKGFKD 
               
               
                   
                   
                 IITTKKFKKVFPTLSLGLDK 
               
               
                   
                   
                 EVRKAYRGGFTWLNDRFKGK 
               
               
                   
                   
                 EIGEGMVFDINSAYPAQMYS 
               
               
                   
                   
                 RLLPYGEPIVFEGKYVWDED 
               
               
                   
                   
                 YPLHIQHIRCEFELKEGYIP 
               
               
                   
                   
                 TIQIKQSLFYKGNEYLKSSG 
               
               
                   
                   
                 GEIADLWLSNVDLELMKEHY 
               
               
                   
                   
                 DLYNVEYISGLKFKATTGLF 
               
               
                   
                   
                 KDFIDKWTYIKTTSYGAIKQ 
               
               
                   
                   
                 LAKLMLNSLYGKFASNPDVT 
               
               
                   
                   
                 GKVPYLKENGALGFRLGEEE 
               
               
                   
                   
                 TKDPVYTPMGVFITAWGRYT 
               
               
                   
                   
                 TITAAQACYDRIIYCDTDSI 
               
               
                   
                   
                 HLTGTKIPDVIKDIVHPKKL 
               
               
                   
                   
                 GYWEHESTFKRAKYLRQKTY 
               
               
                   
                   
                 IQDIYMKRVKGYLVQGSPDD 
               
               
                   
                   
                 YTDIKFSVKCAGMTDKIKKE 
               
               
                   
                   
                 VTFENFKVGFSRKMKPKPVQ 
               
               
                   
                   
                 VPGGVVLVDETFTIK 
               
               
                   
               
               
                   
                 87 
                 MKHMPRKMYSCDFETTTKVE 
               
               
                   
                 Phi29.L142K_Y224K_E 
                 DCRVWAYGYMNIEDHSEYKI 
               
               
                   
                 239G_V250I_L253A_E3 
                 GNSLDEFMAWVLKVQADLYF 
               
               
                   
                 75Y_A437G_E466K_D4 
                 HNLKFDGAFIINWLERNGFK 
               
               
                   
                 76H_A484E_E508R_D5 
                 WSADGLPNTYNTIISRMGQW 
               
               
                   
                 10K_K512Y_E515Q_D5 
                 YMIDICLGYKGKRKIHTVIY 
               
               
                   
                 70E 
                 DSLKKLPFPVKKIAKDFKLT 
               
               
                   
                   
                 VKKGDIDYHKERPVGYKITP 
               
               
                   
                   
                 EEYAYIKNDIQIIAEALLIQ 
               
               
                   
                   
                 FKQGLDRMTAGSDSLKGFKD 
               
               
                   
                   
                 IITTKKFKKVFPTLSLGLDK 
               
               
                   
                   
                 EVRKAYRGGFTWLNDRFKGK 
               
               
                   
                   
                 EIGEGMVFDINSAYPAQMYS 
               
               
                   
                   
                 RLLPYGEPIVFEGKYVWDED 
               
               
                   
                   
                 YPLHIQHIRCEFELKEGYIP 
               
               
                   
                   
                 TIQIKRSRFYKGNEYLKSSG 
               
               
                   
                   
                 GEIADLWLSNVDLELMKEHY 
               
               
                   
                   
                 DLYNVEYISGLKFKATTGLF 
               
               
                   
                   
                 KDFIDKWTYIKTTSYGAIKQ 
               
               
                   
                   
                 LAKLMLNSLYGKFASNPDVT 
               
               
                   
                   
                 GKVPYLKENGALGFRLGEEE 
               
               
                   
                   
                 TKDPVYTPMGVFITAWGRYT 
               
               
                   
                   
                 TITAAQACYDRIIYCDTDSI 
               
               
                   
                   
                 HLTGTKIPDVIKDIVHPKKL 
               
               
                   
                   
                 GYWEHESTFKRAKYLRQKTY 
               
               
                   
                   
                 IQDIYMKRVKGYLVQGSPDD 
               
               
                   
                   
                 YTDIKFSVKCAGMTDKIKKE 
               
               
                   
                   
                 VTFENFKVGFSRKMKPKPVQ 
               
               
                   
                   
                 VPGGVVLVDETFTIK 
               
               
                   
               
               
                   
                 88 
                 MKHMPRKMYSCDFETTTKVE 
               
               
                   
                 Phi29.L142K_Y224K_E 
                 DCRVWAYGYMNIEDHSEYKI 
               
               
                   
                 239G_V250I_L253A_E3 
                 GNSLDEFMAWVLKVQADLYF 
               
               
                   
                 75Y_M429A_A437G_A 
                 HNLKFDGAFIINWLERNGFK 
               
               
                   
                 484E_E508R_D51OK_K 
                 WSADGLPNTYNTIISRMGQW 
               
               
                   
                 512Y_E515Q_D570E 
                 YMIDICLGYKGKRKIHTVIY 
               
               
                   
                   
                 DSLKKLPFPVKKIAKDFKLT 
               
               
                   
                   
                 VKKGDIDYHKERPVGYKITP 
               
               
                   
                   
                 EEYAYIKNDIQIIAEALLIQ 
               
               
                   
                   
                 FKQGLDRMTAGSDSLKGFKD 
               
               
                   
                   
                 IITTKKFKKVFPTLSLGLDK 
               
               
                   
                   
                 EVRKAYRGGFTWLNDRFKGK 
               
               
                   
                   
                 EIGEGMVFDINSAYPAQMYS 
               
               
                   
                   
                 RLLPYGEPIVFEGKYVWDED 
               
               
                   
                   
                 YPLHIQHIRCEFELKEGYIP 
               
               
                   
                   
                 TIQIKRSRFYKGNEYLKSSG 
               
               
                   
                   
                 GEIADLWLSNVDLELMKEHY 
               
               
                   
                   
                 DLYNVEYISGLKFKATTGLF 
               
               
                   
                   
                 KDFIDKWTYIKTTSYGAIKQ 
               
               
                   
                   
                 LAKLMLNSLYGKFASNPDVT 
               
               
                   
                   
                 GKVPYLKENGALGFRLGEEE 
               
               
                   
                   
                 TKDPVYTPAGVFITAWGRYT 
               
               
                   
                   
                 TITAAQACYDRIIYCDTDSI 
               
               
                   
                   
                 HLTGTEIPDVIKDIVDPKKL 
               
               
                   
                   
                 GYWEHESTFKRAKYLRQKTY 
               
               
                   
                   
                 IQDIYMKRVKGY 
               
               
                   
                   
                 LVQGSPDDYTDIKFSVKCAG 
               
               
                   
                   
                 MTDKIKKEVTFENFKVGFSR 
               
               
                   
                   
                 KMKPKPVQVPGGVVLVDETF 
               
               
                   
                   
                 TIK 
               
               
                   
               
               
                   
                 89 
                 MKHMPRKMYSCDFETTTKVE 
               
               
                   
                 Phi29.A134S_L142K_Y2 
                 DCRVWAYGYMNIEDHSEYKI 
               
               
                   
                 24 K_E239G_ V250I_L2 5 
                 GNSLDEFMAWVLKVQADLYF 
               
               
                   
                 3A_E375Y_A437G_A48 
                 HNLKFDGAFIINWLERNGFK 
               
               
                   
                 4E_S487A_E508R_D510 
                 WSADGLPNTYNTIISRMGQW 
               
               
                   
                 K_K512Y_E515Q_I524S 
                 YMIDICLGYKGKRKIHTVIY 
               
               
                   
                 _F526L_D570E 
                 DSLKKLPFPVKKISKDFKLT 
               
               
                   
                   
                 VKKGDIDYHKERPVGYKITP 
               
               
                   
                   
                 EEYAYIKNDIQIIAEALLIQ 
               
               
                   
                   
                 FKQGLDRMTAGSDSLKGFKD 
               
               
                   
                   
                 IITTKKFKKVFPTLSLGLDK 
               
               
                   
                   
                 EVRKAYRGGFTWLNDRFKGK 
               
               
                   
                   
                 EIGEGMVFDINSAYPAQMYS 
               
               
                   
                   
                 RLLPYGEPIVFEGKYVWDED 
               
               
                   
                   
                 YPLHIQHIRCEFELKEGYIP 
               
               
                   
                   
                 TIQIKRSRFYKGNEYLKSSG 
               
               
                   
                   
                 GEIADLWLSNVDLELMKEHY 
               
               
                   
                   
                 DLYNVEYISGLKFKATTGLF 
               
               
                   
                   
                 KDFIDKWTYIKTTSYGAIKQ 
               
               
                   
                   
                 LAKLMLNSLYGKFASNPDVT 
               
               
                   
                   
                 GKVPYLKENGALGFRLGEEE 
               
               
                   
                   
                 TKDPVYTPMGVFITAWGRYT 
               
               
                   
                   
                 TITAAQACYDRIIYCDTDSI 
               
               
                   
                   
                 HLTGTEIPDVIKDIVDPKKL 
               
               
                   
                   
                 GYWEHEATFKRAKYLRQKTY 
               
               
                   
                   
                 IQDIYMKRVKGYLVQGSPDD 
               
               
                   
                   
                 YTDSKLSVKCAGMTDKIKKE 
               
               
                   
                   
                 VTFENFKVGFSRKMKPKPVQ 
               
               
                   
                   
                 VPGGVVLVDETFTIK 
               
               
                   
               
               
                   
                 90 
                 MKHMPRKMYSCDFETTTKVE 
               
               
                   
                 Phi29.Y224K_E239G_V 
                 DCRVWAYGYMNIEDHSEYKI 
               
               
                   
                 250I_L253A_E375Y_A4 
                 GNSLDEFMAWVLKVQADLYF 
               
               
                   
                 37 G_ A484E_S487A_E5 
                 HNLKFDGAFIINWLERNGFK 
               
               
                   
                 08R_D510K_K512Y_E5 
                 WSADGLPNTYNTIISRMGQW 
               
               
                   
                 15Q_I524S_F526L_D57 
                 YMIDICLGYKGKRKIHTVIY 
               
               
                   
                 0M 
                 DSLKKLPFPVKKIAKDFKLT 
               
               
                   
                   
                 VLKGDIDYHKERPVGYKITP 
               
               
                   
                   
                 EEYAYIKNDIQIIAEALLIQ 
               
               
                   
                   
                 FKQGLDRMTAGSDSLKGFKD 
               
               
                   
                   
                 IITTKKFKKVFPTLSLGLDK 
               
               
                   
                   
                 EVRKAYRGGFTWLNDRFKGK 
               
               
                   
                   
                 EIGEGMVFDINSAYPAQMYS 
               
               
                   
                   
                 RLLPYGEPIVFEGKYVWDED 
               
               
                   
                   
                 YPLHIQHIRCEFELKEGYIP 
               
               
                   
                   
                 TIQIKRSRFYKGNEYLKSSG 
               
               
                   
                   
                 GEIADLWLSNVDLELMKEHY 
               
               
                   
                   
                 DLYNVEYISGLKFKATTGLF 
               
               
                   
                   
                 KDFIDKWTYIKTTSYGAIKQ 
               
               
                   
                   
                 LAKLMLNSLYGKFASNPDVT 
               
               
                   
                   
                 GKVPYLKENGALGFRLGEEE 
               
               
                   
                   
                 TKDPVYTPMGVFITAWGRYT 
               
               
                   
                   
                 TITAAQACYDRIIYCDTDSI 
               
               
                   
                   
                 HLTGTEIPDVIKDIVDPKKL 
               
               
                   
                   
                 GYWEHEATFKRAKYLRQKTY 
               
               
                   
                   
                 IQDIYMKRVKGYLVQGSPDD 
               
               
                   
                   
                 YTDSKLSVKCAGMTDKIKKE 
               
               
                   
                   
                 VTFENFKVGFSRKMKPKPVQ 
               
               
                   
                   
                 VPGGVVLVDMTFTIK 
               
               
                   
               
               
                   
                 91 
                 MSRKMFSCDFETTTKLDDCR 
               
               
                   
                 M2.C103S_E236G_V247 
                 VWAYGYMEIGNLDNYKIGNS 
               
               
                   
                 I_L250A_S253A_E372Y 
                 LDEFMQWVMEIQADLYFHNL 
               
               
                   
                 _A434G_A481 E_ V503M 
                 KFDGAFIVNWLEQHGFKWSN 
               
               
                   
                 _E505R_D507K_K509Y 
                 EGLPNTYNTIISKMGQWYMI 
               
               
                   
                 _E512Q 
                 DISFGYKGKRKLHTVIYDSL 
               
               
                   
                   
                 KKLPFPVKKIAKDFQLPLLK 
               
               
                   
                   
                 GDIDYHTERPVGHEITPEEY 
               
               
                   
                   
                 EYIKNDIEIIARALDIQFKQ 
               
               
                   
                   
                 GLDRMTAGSDSLKGFKDILS 
               
               
                   
                   
                 TKKFNKVFPKLSLPMDKEIR 
               
               
                   
                   
                 KAYRGGFTWLNDKYKGKEIG 
               
               
                   
                   
                 EGMVFDINSAYPAQMYSRPL 
               
               
                   
                   
                 PYGAPIVFQGKYEKDEQYPL 
               
               
                   
                   
                 YIQRIRFEFELKEGYIPTIQ 
               
               
                   
                   
                 IKKNPFFKGNEYLKNSGVEP 
               
               
                   
                   
                 VELYLTNVDLELIQEHYELY 
               
               
                   
                   
                 NVEYIDGFKFREKTGLFKDF 
               
               
                   
                   
                 IDKWTYVKTHEYGAKKQLAK 
               
               
                   
                   
                 LMLNSLYGKFASNPDVTGKV 
               
               
                   
                   
                 PYLKDDGSLGFRVGDEEYKD 
               
               
                   
                   
                 PVYTPMGVFITAWGRFTTIT 
               
               
                   
                   
                 AAQACYDRIIYCDTDSIHLT 
               
               
                   
                   
                 GTEVPEIIKDIVDPKKLGYW 
               
               
                   
                   
                 EHESTFKRAKYLRQKTYIQD 
               
               
                   
                   
                 IYMKRVKGYLKQCSPDEATT 
               
               
                   
                   
                 TKFSVKCAGMTDTIKKKVTF 
               
               
                   
                   
                 DNFAVGFSSMGKPKPVQVNG 
               
               
                   
                   
                 GVVLVDSVFTIK 
               
               
                   
               
               
                   
                 92 
                 MKHMPRKMYSCDFETTTKVE 
               
               
                   
                 Phi29.L142K_Y224K_D 
                 DCRVWAYGYMNIED 
               
               
                   
                 235E_E239G_V250A_L 
                 HSEYKIGNSLDEFMAWVLKV 
               
               
                   
                 253H_E375Y_A437G_A 
                 QADLYFHNLKFDGAFIINWL 
               
               
                   
                 484E_E508R_D510K_K 
                 ERNGFKWSADGLPNTYNTII 
               
               
                   
                 512Y_E515Q_D570E 
                 SRMGQWYMIDICLGYKGKRK 
               
               
                   
                   
                 IHTVIYDSLKKLPFPVKKIA 
               
               
                   
                   
                 KDFKLTVKKGDIDYHKERPV 
               
               
                   
                   
                 GYKITPEEYAYIKNDIQIIA 
               
               
                   
                   
                 EALLIQFKQGLDRMTAGSDS 
               
               
                   
                   
                 LKGFKDIITTKKFKKVFPTL 
               
               
                   
                   
                 SLGLDKEVRKAYRGGFTWLN 
               
               
                   
                   
                 ERFKGKEIGEGMVFDANSHY 
               
               
                   
                   
                 PAQMYSRLLPYGEPIVFEGK 
               
               
                   
                   
                 YVWDEDYPLHIQHIRCEFEL 
               
               
                   
                   
                 KEGYIPTIQIKRSRFYKGNE 
               
               
                   
                   
                 YLKSSGGEIADLWLSNVDLE 
               
               
                   
                   
                 LMKEHYDLYNVEYISGLKFK 
               
               
                   
                   
                 ATTGLFKDFIDKWTYIKTTS 
               
               
                   
                   
                 YGAIKQLAKLMLNSLYGKFA 
               
               
                   
                   
                 SNPDVTGKVPYLKENGALGF 
               
               
                   
                   
                 RLGEEETKDPVYTPMGVFIT 
               
               
                   
                   
                 AWGRYTTITAAQACYDRIIY 
               
               
                   
                   
                 CDTDSIHLTGTEIPDVIKDI 
               
               
                   
                   
                 VDPKKLGYWEHESTFKRAKY 
               
               
                   
                   
                 LRQKTYIQDIYMKRVKGYLV 
               
               
                   
                   
                 QGSPDDYTDIKFSVKCAGMT 
               
               
                   
                   
                 DKIKKEVTFENFKVGFSRKM 
               
               
                   
                   
                 KPKPVQVPGGVVLVDETFTI 
               
               
                   
                   
                 K 
               
               
                   
               
               
                   
                 93 
                 MKHMPRKMYSCDFETTTKVE 
               
               
                   
                 Phi29.Y224K_E239G_V 
                 DCRVWAYGYMNIEDHSEYKI 
               
               
                   
                 250I_L253A_E375Y_A4 
                 GNSLDEFMAWVLKVQADLYF 
               
               
                   
                 37G_A484E_E508R_D5 
                 HNLKFDGAFIINWLERNGFK 
               
               
                   
                 10K_K512Y_E515Q 
                 WSADGLPNTYNTIISRMGQW 
               
               
                   
                   
                 YMIDICLGYKGKRKIHTVIY 
               
               
                   
                   
                 DSLKKLPFPVKKIAKDFKLT 
               
               
                   
                   
                 VLKGDIDYHKERPVGYKITP 
               
               
                   
                   
                 EEYAYIKNDIQIIAEALLIQ 
               
               
                   
                   
                 FKQGLDRMTAGSDSLKGFKD 
               
               
                   
                   
                 IITTKKFKKVFPTLSLGLDK 
               
               
                   
                   
                 EVRKAYRGGFTWLNDRFKGK 
               
               
                   
                   
                 EIGEGMVFDINSAYPAQMYS 
               
               
                   
                   
                 RLLPYGEPIVFEGKYVWDED 
               
               
                   
                   
                 YPLHIQHIRCEFELKEGYIP 
               
               
                   
                   
                 TIQIKRSRFYKGNEYLKSSG 
               
               
                   
                   
                 GEIADLWLSNVDLELMKEHY 
               
               
                   
                   
                 DLYNVEYISGLKFKATTGLF 
               
               
                   
                   
                 KDFIDKWTYIKTTSYGAIKQ 
               
               
                   
                   
                 LAKLMLNSLYGKFASNPDVT 
               
               
                   
                   
                 GKVPYLKENGALGFRLGEEE 
               
               
                   
                   
                 TKDPVYTPMGVFITAWGRYT 
               
               
                   
                   
                 TITAAQACYDRHYCDTDSIH 
               
               
                   
                   
                 LTGTEIPDVIKDrVDPKKLG 
               
               
                   
                   
                 YWEHESTFKRAKYLRQKTYI 
               
               
                   
                   
                 QDIYMKRVKGYLVQGSPDDY 
               
               
                   
                   
                 TDIKFSVKCAGMTDKIKKEV 
               
               
                   
                   
                 TFENFKVGFSRKMKPKPVQV 
               
               
                   
                   
                 PGGVVLVDDTFTIK 
               
               
                   
               
               
                   
                 94 
                 MKHMPRKMYSCDFETTTKVE 
               
               
                   
                 Phi29.V141K_L142K_Y 
                 DCRVWAYGYMNIEDHSEYKI 
               
               
                   
                 224K_E239G_V250I_L2 
                 GNSLDEFMAWVLKVQADLYF 
               
               
                   
                 53A_E375Y_A437G_A4 
                 HNLKFDGAFIINWLERNGFK 
               
               
                   
                 84E_E508R_D510K_K5 
                 WSADGLPNTYNTIISRMGQW 
               
               
                   
                 12Y_E515Q 
                 YMIDICLGYKGKRKIHTVIY 
               
               
                   
                   
                 DSLKKLPFPVKKIAKDFKLT 
               
               
                   
                   
                 KKKGDIDYHKERPVGYKITP 
               
               
                   
                   
                 EEYAYIKNDIQIIAEALLIQ 
               
               
                   
                   
                 FKQGLDRMTAGSDSLKGFKD 
               
               
                   
                   
                 IITTKKFKKVFPTLSLGLDK 
               
               
                   
                   
                 EVRKAYRGGFTWLNDRFKGK 
               
               
                   
                   
                 EIGEGMVFDINSAYPAQMYS 
               
               
                   
                   
                 RLLPYGEPIVFEGKYVWDED 
               
               
                   
                   
                 YPLHIQHIRCEFELKEGYIP 
               
               
                   
                   
                 TIQIKRSRFYKGNEYLKSSG 
               
               
                   
                   
                 GEIADLWLSNVDLELMKEHY 
               
               
                   
                   
                 DLYNVEYISGLKFKATTGLF 
               
               
                   
                   
                 KDFIDKWTYIKTTSYGAIKQ 
               
               
                   
                   
                 LAKLMLNSLYGKFASNPDVT 
               
               
                   
                   
                 GKVPYLKENGALGFRLGEEE 
               
               
                   
                   
                 TKDPVYTPMGVFITAWGRYT 
               
               
                   
                   
                 TITAAQACYDRIIYCDTDSI 
               
               
                   
                   
                 HLTGTEIPDVIKDIVDPKKL 
               
               
                   
                   
                 GYWEHESTFKRAKYLRQKTY 
               
               
                   
                   
                 IQDIYMKRVKGYLVQGSPDD 
               
               
                   
                   
                 YTDIKFSVKCAGMTDKIKKE 
               
               
                   
                   
                 VTFENFKVGFSRKMKPKPVQ 
               
               
                   
                   
                 VPGGVVLVDDTFTIK 
               
               
                   
               
               
                   
                 112 
                 MKHMPRKMYSCDFETTTKVE 
               
               
                   
                 Phi29.K135Q_L142K_Y 
                 DCRVWAYGYMNIEDHSEYKI 
               
               
                   
                 224K_E239G_V250I_L2 
                 GNSLDEFMAWVLKVQADLYF 
               
               
                   
                 53A_R306Q_R308L_E3 
                 HNLKFDGAFIINWLERNGFK 
               
               
                   
                 75Y_A437G_E466K_D4 
                 WSADGLPNTYNTIISRMGQW 
               
               
                   
                 76H_A484E_E508R_D5 
                 YMIDICLGYKGKRKIHTVIY 
               
               
                   
                 10R_K512Y_E515Q_D5 
                 DSLKKLPFPVKKIAQDFKLT 
               
               
                   
                 70S_T571V 
                 VKKGDIDYHKERPVGYKITP 
               
               
                   
                   
                 EEYAYIKNDIQIIAEALLIQ 
               
               
                   
                   
                 FKQGLDRMTAGSDSLKGFKD 
               
               
                   
                   
                 IITTKKFKKVFPTLSLGLDK 
               
               
                   
                   
                 EVRKAYRGGFTWLNDRFKGK 
               
               
                   
                   
                 EIGEGMVFDINSAYPAQMYS 
               
               
                   
                   
                 RLLPYGEPIVFEGKYVWDED 
               
               
                   
                   
                 YPLHIQHIRCEFELKEGYIP 
               
               
                   
                   
                 TIQIKQSLFYKGNEYLKSSG 
               
               
                   
                   
                 GEIADLWLSNVDLELMKEHY 
               
               
                   
                   
                 DLYNVEYISGLKFKATTGLF 
               
               
                   
                   
                 KDFIDKWTYIKTTSYGAIKQ 
               
               
                   
                   
                 LAKLMLNSLYGKFASNPDVT 
               
               
                   
                   
                 GKVPYLKENGALGFRLGEEE 
               
               
                   
                   
                 TKDPVYTPMGVFITAWGRYT 
               
               
                   
                   
                 TITAAQACYDRIIYCDTDSI 
               
               
                   
                   
                 HLTGTKIPDVIKDIVHPKKL 
               
               
                   
                   
                 GYWEHESTFKRAKYLRQKTY 
               
               
                   
                   
                 IQDIYMKRVRGYLVQGSPDD 
               
               
                   
                   
                 YTDIKFSVKCAGMTDKIKKE 
               
               
                   
                   
                 VTFENFKVGFSRKMKPKPVQ 
               
               
                   
                   
                 VPGGVVLVDSVFTIK 
               
               
                   
               
               
                   
                 113 
                 MKHMPRKMYSCDFETTTKVE 
               
               
                   
                 Phi29.K131E_K135Q_L 
                 DCRVWAYGYMNIEDHSEYKI 
               
               
                   
                 142K_Y224K_E239G_V 
                 GNSLDEFMAWVLKVQADLYF 
               
               
                   
                 250I_L253A_E375Y_A4 
                 HNLKFDGAFIINWLERNGFK 
               
               
                   
                 37G_A484E_E508R_D5 
                 WSADGLPNTYNTIISRMGQW 
               
               
                   
                 10R_K512Y_E515Q_D5 
                 YMIDICLGYKGKRKIHTVIY 
               
               
                   
                 23R_P558A_D570S_T57 
                 DSLKKLPFPVEKIAQDFKLT 
               
               
                   
                 IV 
                 VKKGDIDYHKERPVGYKITP 
               
               
                   
                   
                 EEYAYIKNDIQIIAEALLIQ 
               
               
                   
                   
                 FKQGLDRMTAGSDSLKGFKD 
               
               
                   
                   
                 IITTKKFKKVFPTLSLGLDK 
               
               
                   
                   
                 EVRKAYRGGFTWLNDRFKGK 
               
               
                   
                   
                 EIGEGMVFDINSAYPAQMYS 
               
               
                   
                   
                 RLLPYGEPIVFEGKYVWDED 
               
               
                   
                   
                 YPLHIQHIRCEFELKEGYIP 
               
               
                   
                   
                 TIQIKRSRFYKGNEYLKSSG 
               
               
                   
                   
                 GEIADLWLSNVDLELMKEHY 
               
               
                   
                   
                 DLYNVEYISGLKFKATTGLF 
               
               
                   
                   
                 KDFIDKWTYIKTTSYGAIKQ 
               
               
                   
                   
                 LAKLMLNSLYGKFASNPDVT 
               
               
                   
                   
                 GKVPYLKENGALGFRLGEEE 
               
               
                   
                   
                 TKDPVYTPMGVFITAWGRYT 
               
               
                   
                   
                 TITAAQACYDRHYCDTDSIH 
               
               
                   
                   
                 LTGTEIPDVIKDrVDPKKLG 
               
               
                   
                   
                 YWEHESTFKRAKYLRQKTYI 
               
               
                   
                   
                 QDIYMKRVRGYLVQGSPDDY 
               
               
                   
                   
                 TRIKFSVKCAGMTDKIKKEV 
               
               
                   
                   
                 TFENFKVGFSRKMKPKAVQV 
               
               
                   
                   
                 PGGVVLVDSVFTIK 
               
               
                   
               
               
                   
                 114 
                 MKHMPRKMYSCDFETTTKVE 
               
               
                   
                 Phi29.A49E_C106S_K11 
                 DCRVWAYGYMNIEDHSEYKI 
               
               
                   
                 4R_K131E_K135Q_L14 
                 GNSLDEFMEWVLKVQADLYF 
               
               
                   
                 2K_Y224K_E239G_V25 
                 HNLKFDGAFIINWLERNGFK 
               
               
                   
                 0I_L253A_Y369E_E375 
                 WSADGLPNTYNTIISRMGQW 
               
               
                   
                 Y_A437G_D476H_A484 
                 YMIDISLGYKGKRRIHTVIY 
               
               
                   
                 E_E508R_D510K_K512 
                 DSLKKLPFPVEKIAQDFKLT 
               
               
                   
                 Y_E515Q_D523R_D570 
                 VKKGDIDYHKERPVGYKITP 
               
               
                   
                 S_T571V 
                 EEYAYIKNDIQIIAEALLIQ 
               
               
                   
                   
                 FKQGLDRMTAGSDSLKGFKD 
               
               
                   
                   
                 IITTKKFKKVFPTLSLGLDK 
               
               
                   
                   
                 EVRKAYRGGFTWLNDRFKGK 
               
               
                   
                   
                 EIGEGMVFDINSAYPAQMYS 
               
               
                   
                   
                 RLLPYGEPIVFEGKYVWDED 
               
               
                   
                   
                 YPLHIQHIRCEFELKEGYIP 
               
               
                   
                   
                 TIQIKRSRFYKGNEYLKSSG 
               
               
                   
                   
                 GEIADLWLSNVDLELMKEHY 
               
               
                   
                   
                 DLYNVEYISGLKFKATTGLF 
               
               
                   
                   
                 KDFIDKWTEIKTTSYGAIKQ 
               
               
                   
                   
                 LAKLMLNSLYGKFASNPDVT 
               
               
                   
                   
                 GKVPYLKENGALGFRLGEEE 
               
               
                   
                   
                 TKDPVYTPMGVFITAWGRYT 
               
               
                   
                   
                 TITAAQACYDRIIYCDTDSI 
               
               
                   
                   
                 HLTGTEIPDVIKDIVHPKKL 
               
               
                   
                   
                 GYWEHESTFKRAKYLRQKTY 
               
               
                   
                   
                 IQDIYMKRVKGYLVQGSPDD 
               
               
                   
                   
                 YTRIKFSVKCAGMTDKIKKE 
               
               
                   
                   
                 VTFENFKVGFSRKMKPKPVQ 
               
               
                   
                   
                 VPGGVVLVDSVFTIK 
               
               
                   
               
               
                   
                 115 
                 MKHMPRKMYSCDFETTTKVE 
               
               
                   
                 Phi29.K135Q_K138Q_L 
                 DCRVWAYGYMNIEDHSEYKI 
               
               
                   
                 142K_Y224K_E239G_V 
                 GNSLDEFMAWVLKVQADLYF 
               
               
                   
                 250I_L253A_R306Q_R3 
                 HNLKFDGAFIINWLERNGFK 
               
               
                   
                 08L_E375Y_A437G_E4 
                 WSADGLPNTYNTIISRMGQW 
               
               
                   
                 66_KD476H_A484E_E5 
                 YMIDICLGYKGKRKIHTVIY 
               
               
                   
                 08R_D510K_K512Y_E5 
                 DSLKKLPFPVKKIAQDFQLT 
               
               
                   
                 15Q_I524T_P558A_D57 
                 VKKGDIDYHKERPVGYKITP 
               
               
                   
                 0S_T571V 
                 EEYAYIKNDIQIIAEALLIQ 
               
               
                   
                   
                 FKQGLDRMTAGSDSLKGFKD 
               
               
                   
                   
                 IITTKKFKKVFPTLSLGLDK 
               
               
                   
                   
                 EVRKAYRGGFTWLNDRFKGK 
               
               
                   
                   
                 EIGEGMVFDINSAYPAQMYS 
               
               
                   
                   
                 RLLPYGEPIVFEGKYVWDED 
               
               
                   
                   
                 YPLHIQHIRCEFELKEGYIP 
               
               
                   
                   
                 TIQIKQSLFYKGNEYLKSSG 
               
               
                   
                   
                 GEIADLWLSNVDLELMKEHY 
               
               
                   
                   
                 DLYNVEYISGLKFKATTGLF 
               
               
                   
                   
                 KDFIDKWTYIKTTSYGAIKQ 
               
               
                   
                   
                 LAKLMLNSLYGKFASNPDVT 
               
               
                   
                   
                 GKVPYLKENGALGFRLGEEE 
               
               
                   
                   
                 TKDPVYTPMGVFITAWGRYT 
               
               
                   
                   
                 TITAAQACYDRirYCDTDSI 
               
               
                   
                   
                 HLTGTKIPDVIKDIVHPKKL 
               
               
                   
                   
                 GYWEHESTFKRAKYLRQKTY 
               
               
                   
                   
                 IQDIYMKRVKGYLVQGSPDD 
               
               
                   
                   
                 YTDTKFSVKCAGMTDKIKKE 
               
               
                   
                   
                 VTFENFKVGFSRKMKPKAVQ 
               
               
                   
                   
                 VPGGVVLVDSVFTIK 
               
               
                   
               
               
                   
                 116 
                 MKHMPRKMYSCDFETTTKVE 
               
               
                   
                 Phi29.K135Q_K138Q_L 
                 DCRVWAYGYMNIEDHSEYKI 
               
               
                   
                 142K_Y224K_E239G_V 
                 GNSLDEFMAWVLKVQADLYF 
               
               
                   
                 250I_L253A_R306Q_R3 
                 HNLKFDGAFIINWLERNGFK 
               
               
                   
                 08L_E375Y_A437G_E4 
                 WSADGLPNTYNTIISRMGQW 
               
               
                   
                 66K_V4751_D476H_A4 
                 YMIDICLGYKGKRKIHTVIY 
               
               
                   
                 84E_E508R_D510K_K5 
                 DSLKKLPFPVKKIAQDFQLT 
               
               
                   
                 12Y_E515Q_I524T_P55 
                 VKKGDIDYHKERPVGYKITP 
               
               
                   
                 8A_D570S_T57IV 
                 EEYAYIKNDIQIIAEALLIQ 
               
               
                   
                   
                 FKQGLDRMTAGSDSLKGFKD 
               
               
                   
                   
                 IITTKKFKKVFPTLSLGLDK 
               
               
                   
                   
                 EVRKAYRGGFTWLNDRFKGK 
               
               
                   
                   
                 EIGEGMVFDINSAYPAQMYS 
               
               
                   
                   
                 RLLPYGEPIVFEGKYVWDED 
               
               
                   
                   
                 YPLHIQHIRCEFELKEGYIP 
               
               
                   
                   
                 TIQIKQSLFYKGNEYLKSSG 
               
               
                   
                   
                 GEIADLWLSNVDLELMKEHY 
               
               
                   
                   
                 DLYNVEYISGLKFKATTGLF 
               
               
                   
                   
                 KDFIDKWTYIKTTSYGAIKQ 
               
               
                   
                   
                 LAKLMLNSLYGKFASNPDVT 
               
               
                   
                   
                 GKVPYLKENGALGFRLGEEE 
               
               
                   
                   
                 TKDPVYTPMGVFITAWGRYT 
               
               
                   
                   
                 TITAAQACYDRIIYCDTDSI 
               
               
                   
                   
                 HLTGTKIPDVIKDIIHPKKL 
               
               
                   
                   
                 GYWEHESTFKRAKYLRQKTY 
               
               
                   
                   
                 IQDIYMKRVKGYLVQGSPDD 
               
               
                   
                   
                 YTDTKFSVKCAGMTDKIKKE 
               
               
                   
                   
                 VTFENFKVGFSRKMKPKAVQ 
               
               
                   
                   
                 VPGGVVLVDSVFTIK 
               
               
                   
               
               
                   
                 117 
                 MKHMPRKMYSCDFETTTKVE 
               
               
                   
                 Phi29.K135Q_K138Q_L 
                 DCRVWAYGYMNIEDHSEYKI 
               
               
                   
                 142K_Y224K_E239G_V 
                 GNSLDEFMAWVLKVQADLYF 
               
               
                   
                 250I_L253A_R306Q_R3 
                 HNLKFDGAFIINWLERNGFK 
               
               
                   
                 08L_T368S_E375Y_A43 
                 WSADGLPNTYNTIISRMGQW 
               
               
                   
                 7G_E466K_D476H_A48 
                 YMIDICLGYKGKRKIHTVIY 
               
               
                   
                 4E_E508R_D510K_K51 
                 DSLKKLPFPVKKIAQDFQLT 
               
               
                   
                 2Y_E515Q_I524T_P558 
                 VKKGDIDYHKERPVGYKITP 
               
               
                   
                 A_D570S_T571V 
                 EEYAYIKNDIQIIAEALLIQ 
               
               
                   
                   
                 FKQGLDRMTAGSDSLKGFKD 
               
               
                   
                   
                 IITTKKFKKVFPTLSLGLDK 
               
               
                   
                   
                 EVRKAYRGGFTWLNDRFKGK 
               
               
                   
                   
                 EIGEGMVFDINSAYPAQMYS 
               
               
                   
                   
                 RLLPYGEPIVFEGKYVWDED 
               
               
                   
                   
                 YPLHIQHIRCEFELKEGYIP 
               
               
                   
                   
                 TIQIKQSLFYKGNEYLKSSG 
               
               
                   
                   
                 GEIADLWLSNVDLELMKEHY 
               
               
                   
                   
                 DLYNVEYISGLKFKATTGLF 
               
               
                   
                   
                 KDFIDKWSYIKTTSYGAIKQ 
               
               
                   
                   
                 LAKLMLNSLYGKFASNPDVT 
               
               
                   
                   
                 GKVPYLKENGALGFRLGEEE 
               
               
                   
                   
                 TKDPVYTPMGVFITAWGRYT 
               
               
                   
                   
                 TITAAQACYDRIIYCDTDSI 
               
               
                   
                   
                 HLTGTKIPDVIKDIVHPKKL 
               
               
                   
                   
                 GYWEHESTFKRAKYLRQKTY 
               
               
                   
                   
                 IQDIYMKRVKGYLVQGSPDD 
               
               
                   
                   
                 YTDTKFSVKCAGMTDKIKKE 
               
               
                   
                   
                 VTFENFKVGFSRKMKPKAVQ 
               
               
                   
                   
                 VPGGVVLVDSVFTIK 
               
               
                   
               
               
                   
                 118 
                 MKHMPRKMYSCDFETTTKVED 
               
               
                   
                 Phi29.K135Q_K138Q_L 
                 CRVWAYGYMNIEDHSEYKIG 
               
               
                   
                 142K_Y224K_E239G_V 
                 NSLDEFMAWVLKVQADLYFH 
               
               
                   
                 250I_L253A_R306Q_R3 
                 NLKFDGAFIINWLERNGFKW 
               
               
                   
                 08L_T368S_E375Y_A43 
                 SADGLPNTYNTIISRMGQWY 
               
               
                   
                 7G_E466K_V475I_D476 
                 MIDICLGYKGKRKIHTVIYD 
               
               
                   
                 H_A484E_E508R_D510 
                 SLKKLPFPVKKIAQDFQLTV 
               
               
                   
                 K_K512Y_E515Q_P558 
                 KKGDIDYHKERPVGYKITPE 
               
               
                   
                 A_D570S_T571V 
                 EYAYIKNDIQIIAEALLIQF 
               
               
                   
                   
                 KQGLDRMTAGSDSLKGFKDI 
               
               
                   
                   
                 ITTKKFKKVFPTLSLGLDKE 
               
               
                   
                   
                 VRKAYRGGFTWLNDRFKGKE 
               
               
                   
                   
                 IGEGMVFDINSAYPAQMYSR 
               
               
                   
                   
                 LLPYGEPIVFEGKYVWDEDY 
               
               
                   
                   
                 PLHIQHIRCEFELKEGYIPT 
               
               
                   
                   
                 IQIKQSLFYKGNEYLKSSGG 
               
               
                   
                   
                 EIADLWLSNVDLELMKEHYD 
               
               
                   
                   
                 LYNVEYISGLKFKATTGLFK 
               
               
                   
                   
                 DFIDKWSYIKTTSYGAIKQL 
               
               
                   
                   
                 AKLMLNSLYGKFASNPDVTG 
               
               
                   
                   
                 KVPYLKENGALGFRLGEEET 
               
               
                   
                   
                 KDPVYTPMGVFITAWGRYTT 
               
               
                   
                   
                 ITAAQACYDRIIYCDTDSIH 
               
               
                   
                   
                 LTGTKIPDVIKDIIHPKKLG 
               
               
                   
                   
                 YWEHESTFKRAKYLRQKTYI 
               
               
                   
                   
                 QDIYMKRVKGYLVQGSPDDY 
               
               
                   
                   
                 TDIKFSVKCAGMTDKIKKEV 
               
               
                   
                   
                 TFENFKVGFSRKMKPKAVQV 
               
               
                   
                   
                 PGGVVLVDSVFTIK 
               
               
                   
               
               
                   
                 119 
                 MKHMPRKMYSCDFETTTKVE 
               
               
                   
                 Phi29.L44A_K135Q_K1 
                 DCRVWAYGYMNIEDHSEYKI 
               
               
                   
                 38Q_L142K_Y224K_E2 
                 GNSADEFMAWVLKVQADLYF 
               
               
                   
                 39G_V250I_L253A_R30 
                 HNLKFDGAFIINWLERNGFK 
               
               
                   
                 6Q_R308L_E375Y_A43 
                 WSADGLPNTYNTIISRMGQW 
               
               
                   
                 7G_E466K_D476H_A48 
                 YMIDICLGYKGKRKIHTVIY 
               
               
                   
                 4E_S487A_E508R_D510 
                 DSLKKLPFPVKKIAQDFQLT 
               
               
                   
                 K_K512Y_E515Q_P558 
                 VKKGDIDYHKERPVGYKITP 
               
               
                   
                 A_D570S_T571V 
                 EEYAYIKNDIQIIAEALLIQ 
               
               
                   
                   
                 FKQGLDRMTAGSDSLKGFKD 
               
               
                   
                   
                 IITTKKFKKVFPTLSLGLDK 
               
               
                   
                   
                 EVRKAYRGGFTWLNDRFKGK 
               
               
                   
                   
                 EIGEGMVFDINSAYPAQMYS 
               
               
                   
                   
                 RLLPYGEPIVFEGKYVWDED 
               
               
                   
                   
                 YPLHIQHIRCEFELKEGYIP 
               
               
                   
                   
                 TIQIKQSLFYKGNEYLKSSG 
               
               
                   
                   
                 GEIADLWLSNVDLELMKEHY 
               
               
                   
                   
                 DLYNVEYISGLKFKATTGLF 
               
               
                   
                   
                 KDFIDKWTYIKTTSYGAIKQ 
               
               
                   
                   
                 LAKLMLNSLYGKFASNPDVT 
               
               
                   
                   
                 GKVPYLKENGALGFRLGEEE 
               
               
                   
                   
                 TKDPVYTPMGVFITAWGRYT 
               
               
                   
                   
                 TITAAQACYDRIIYCDTDSI 
               
               
                   
                   
                 HLTGTKIPDVIKDIVHPKKL 
               
               
                   
                   
                 GYWEHEATFKRAKYLRQKTY 
               
               
                   
                   
                 IQDIYMKRVKGYLVQGSPDD 
               
               
                   
                   
                 YTDIKFSVKCAGMTDKIKKE 
               
               
                   
                   
                 VTFENFKVGFSRKMKPKAVQ 
               
               
                   
                   
                 VPGGVVLVDSVFTIK 
               
               
                   
               
               
                   
                 120 
                 MKHMPRKMYSCDFETTTKVE 
               
               
                   
                 Phi29.K135Q_L142K_Y 
                 DCRVWAYGYMNIEDHSEYKI 
               
               
                   
                 224K_E239G_V250I_L2 
                 GNSLDEFMAWVLKVQADLYF 
               
               
                   
                 53A_R306Q_R308L_T3 
                 HNLKFDGAFIINWLERNGFK 
               
               
                   
                 68S_E375Y_A437G_E4 
                 WSADGLPNTYNTIISRMGQW 
               
               
                   
                 66K_D476H_A484E_E5 
                 YMIDICLGYKGKRKIHTVIY 
               
               
                   
                 08R_D510R_K512Y_E5 
                 DSLKKLPFPVKKIAQDFKLT 
               
               
                   
                 15Q_P558A_D570S_T57 
                 VKKGDIDYHKERPVGYKITP 
               
               
                   
                 1V 
                 EEYAYIKNDIQIIAEALLIQ 
               
               
                   
                   
                 FKQGLDRMTAGSDSLKGFKD 
               
               
                   
                   
                 IITTKKFKKVFPTLSLGLDK 
               
               
                   
                   
                 EVRKAYRGGFTWLNDRFKGK 
               
               
                   
                   
                 EIGEGMVFDINSAYPAQMYS 
               
               
                   
                   
                 RLLPYGEPIVFEGKYVWDED 
               
               
                   
                   
                 YPLHIQHIRCEFELKEGYIP 
               
               
                   
                   
                 TIQIKQSLFYKGNEYLKSSG 
               
               
                   
                   
                 GEIADLWLSNVDLELMKEHY 
               
               
                   
                   
                 DLYNVEYISGLKFKATTGLF 
               
               
                   
                   
                 KDFIDKWSYIKTTSYGAIKQ 
               
               
                   
                   
                 LAKLMLNSLYGKFASNPDVT 
               
               
                   
                   
                 GKVPYLKENGALGFRLGEEE 
               
               
                   
                   
                 TKDPVYTPMGVFITAWGRYT 
               
               
                   
                   
                 TITAAQACYDRIIYCDTDSI 
               
               
                   
                   
                 HLTGTKIPDVIKDIVHPKKL 
               
               
                   
                   
                 GYWEHESTFKRAKYLRQKTY 
               
               
                   
                   
                 IQDIYMKRVRGYLVQGSPDD 
               
               
                   
                   
                 YTDIKFSVKCAGMTDKIKKE 
               
               
                   
                   
                 VTFENFKVGFSRKMKPKAVQ 
               
               
                   
                   
                 VPGGVVLVDSVFTIK 
               
               
                   
               
               
                   
                 121 
                 MKHMPRKMYSCDFETTTKVE 
               
               
                   
                 Phi29.A49E_C106S_K11 
                 DCRVWAYGYMNIEDHSEYKI 
               
               
                   
                 4R_K135Q_L142K_Y22 
                 GNSLDEFMEWVLKVQADLYF 
               
               
                   
                 4K_E239G_V250I_L253 
                 HNLKFDGAFIINWLERNGFK 
               
               
                   
                 A_R306Q_R308L_E375 
                 WSADGLPNTYNTIISRMGQW 
               
               
                   
                 Y_A437G_E466K_D476 
                 YMIDISLGYKGKRRIHTVIY 
               
               
                   
                 H_A484E_E508R_D510 
                 DSLKKLPFPVKKIAQDFKLT 
               
               
                   
                 R_K512Y_E515Q_K536 
                 VKKGDIDYHKERPVGYKITP 
               
               
                   
                 Q_K539Q_D570S_T571 
                 EEYAYIKNDIQIIAEALLIQ 
               
               
                   
                 V 
                 FKQGLDRMTAGSDSLKGFKD 
               
               
                   
                   
                 IITTKKFKKVFPTLSLGLDK 
               
               
                   
                   
                 EVRKAYRGGFTWLNDRFKGK 
               
               
                   
                   
                 EIGEGMVFDINSAYPAQMYS 
               
               
                   
                   
                 RLLPYGEPIVFEGKYVWDED 
               
               
                   
                   
                 YPLHIQHIRCEFELKEGYIP 
               
               
                   
                   
                 TIQIKQSLFYKGNEYLKSSG 
               
               
                   
                   
                 GEIADLWLSNVDLELMKEHY 
               
               
                   
                   
                 DLYNVEYISGLKFKATTGLF 
               
               
                   
                   
                 KDFIDKWTYIKTTSYGAIKQ 
               
               
                   
                   
                 LAKLMLNSLYGKFASNPDVT 
               
               
                   
                   
                 GKVPYLKENGALGFRLGEEE 
               
               
                   
                   
                 TKDPVYTPMGVFITAWGRYT 
               
               
                   
                   
                 TITAAQACYDRIIYCDTDSI 
               
               
                   
                   
                 HLTGTKIPDVIKDIVHP 
               
               
                   
                   
                 KKLGYWEHESTFKRAKYLRQ 
               
               
                   
                   
                 KTYIQDIYMKRVRGYLVQGS 
               
               
                   
                   
                 PDDYTDIKFSVKCAGMTDQI 
               
               
                   
                   
                 KQEVTFENFKVGFSRKMKPK 
               
               
                   
                   
                 PVQVPGGVVLVDSVFTIK 
               
               
                   
               
               
                   
                 122 
                 MKHMPRKMYSCDFETTTKVE 
               
               
                   
                 Phi29.L44A_K135Q_K1 
                 DCRVWAYGYMNIEDHSEYKI 
               
               
                   
                 3BQ_L142K_Y224K_E2 
                 GNSADEFMAWVLKVQADLYF 
               
               
                   
                 39G_V250I_L253A_R30 
                 HNLKFDGAFIINWLERNGFK 
               
               
                   
                 6Q_R308L_T368S_E375 
                 WSADGLPNTYNTIISRMGQW 
               
               
                   
                 Y_A437G_E466K_D476 
                 YMIDICLGYKGKRKIHTVIY 
               
               
                   
                 H_A484E_E508R_D510 
                 DSLKKLPFPVKKIAQDFQLT 
               
               
                   
                 K_K512Y_E515Q_P558 
                 VKKGDIDYHKERPVGYKITP 
               
               
                   
                 A_D570S_T571V 
                 EEYAYIKNDIQIIAEALLIQ 
               
               
                   
                   
                 FKQGLDRMTAGSDSLKGFKD 
               
               
                   
                   
                 IITTKKFKKVFPTLSLGLDK 
               
               
                   
                   
                 EVRKAYRGGFTWLNDRFKGK 
               
               
                   
                   
                 EIGEGMVFDINSAYPAQMYS 
               
               
                   
                   
                 RLLPYGEPIVFEGKYVWDED 
               
               
                   
                   
                 YPLHIQHIRCEFELKEGYIP 
               
               
                   
                   
                 TIQIKQSLFYKGNEYLKSSG 
               
               
                   
                   
                 GEIADLWLSNVDLELMKEHY 
               
               
                   
                   
                 DLYNVEYISGLKFKATTGLF 
               
               
                   
                   
                 KDFIDKWSYIKTTSYGAIKQ 
               
               
                   
                   
                 LAKLMLNSLYGKFASNPDVT 
               
               
                   
                   
                 GKVPYLKENGALGFRLGEEE 
               
               
                   
                   
                 TKDPVYTPMGVFITAWGRYT 
               
               
                   
                   
                 TITAAQACYDRIIYCDTDSI 
               
               
                   
                   
                 HLTGTKIPDVIKDIVHPKKL 
               
               
                   
                   
                 GYWEHESTFKRAKYLRQKTY 
               
               
                   
                   
                 IQDIYMKRVKGYLVQGSPDD 
               
               
                   
                   
                 YTDIKFSVKCAGMTDKIKKE 
               
               
                   
                   
                 VTFENFKVGFSRKMKPKAVQ 
               
               
                   
                   
                 VPGGVVLVDSVFTIK 
               
               
                   
               
               
                   
                 123 
                 MKHMPRKMYSCDFETTTKVE 
               
               
                   
                 Phi29.L142K_Y224K_E 
                 DCRVWAYGYMNIEDHSEYKI 
               
               
                   
                 239G_V250I_L253A_R3 
                 GNSLDEFMAWVLKVQADLYF 
               
               
                   
                 06Q_R308L_E375Y_A4 
                 HNLKFDGAFIINWLERNGFK 
               
               
                   
                 37G_E466K_D476H_A4 
                 WSADGLPNTYNTIISRMGQW 
               
               
                   
                 84E_E508R_D510K_K5 
                 YMIDICLGYKGKRKIHTVIY 
               
               
                   
                 12Y_E515Q_P558A_D5 
                 DSLKKLPFPVKKIAKDFKLT 
               
               
                   
                 70T_T571A 
                 VKKGDIDYHKERPVGYKITP 
               
               
                   
                   
                 EEYAYIKNDIQIIAEALLIQ 
               
               
                   
                   
                 FKQGLDRMTAGSDSLKGFKD 
               
               
                   
                   
                 IITTKKFKKVFPTLSLGLDK 
               
               
                   
                   
                 EVRKAYRGGFTWLNDRFKGK 
               
               
                   
                   
                 EIGEGMVFDINSAYPAQMYS 
               
               
                   
                   
                 RLLPYGEPIVFEGKYVWDED 
               
               
                   
                   
                 YPLHIQHIRCEFELKEGYIP 
               
               
                   
                   
                 TIQIKQSLFYKGNEYLKSSG 
               
               
                   
                   
                 GEIADLWLSNVDLELMKEHY 
               
               
                   
                   
                 DLYNVEYISGLKFKATTGLF 
               
               
                   
                   
                 KDFIDKWTYIKTTSYGAIKQ 
               
               
                   
                   
                 LAKLMLNSLYGKFASNPDVT 
               
               
                   
                   
                 GKVPYLKENGALGFRLGEEE 
               
               
                   
                   
                 TKDPVYTPMGVFITAWGRYT 
               
               
                   
                   
                 TITAAQACYDRIIYCDTDSI 
               
               
                   
                   
                 HLTGTKIPDVIKDIVHPKKL 
               
               
                   
                   
                 GYWEHESTFKRAKYLRQKTY 
               
               
                   
                   
                 IQDIYMKRVKGYLVQGSPDD 
               
               
                   
                   
                 YTDIKFSVKCAGMTDKIKKE 
               
               
                   
                   
                 VTFENFKVGFSRKMKPKAVQ 
               
               
                   
                   
                 VPGGVVLVDTAFTIK 
               
               
                   
               
               
                   
                 124 
                 MKHMPRKMYSCDFETTTKVE 
               
               
                   
                 Phi29.K138C_L142K_Y 
                 DCRVWAYGYMNIEDHSEYKI 
               
               
                   
                 224K_E239G_V250I_L2 
                 GNSLDEFMAWVLKVQADLYF 
               
               
                   
                 53A_R306Q_R308L_E3 
                 HNLKFDGAFIINWLERNGFK 
               
               
                   
                 75Y_A437G_E466K_D4 
                 WSADGLPNTYNTIISRMGQW 
               
               
                   
                 76H_A484E_E508R_D5 
                 YMIDICLGYKGKRKIHTVIY 
               
               
                   
                 10K_K512Y_E515Q_D5 
                 DSLKKLPFPVKKIAKDFCLT 
               
               
                   
                 70S_T571V 
                 VKKGDIDYHKERPVGYKITP 
               
               
                   
                   
                 EEYAYIKNDIQIIAEALLIQ 
               
               
                   
                   
                 FKQGLDRMTAGSDSLKGFKD 
               
               
                   
                   
                 IITTKKFKKVFPTLSLGLDK 
               
               
                   
                   
                 EVRKAYRGGFTWLNDRFKGK 
               
               
                   
                   
                 EIGEGMVFDINSAYPAQMYS 
               
               
                   
                   
                 RLLPYGEPIVFEGKYVWDED 
               
               
                   
                   
                 YPLHIQHIRCEFELKEGYIP 
               
               
                   
                   
                 TIQIKQSLFYKGNEYLKSSG 
               
               
                   
                   
                 GEIADLWLSNVDLELMKEHY 
               
               
                   
                   
                 DLYNVEYISGLKFKATTGLF 
               
               
                   
                   
                 KDFIDKWTYIKTTSYGAIKQ 
               
               
                   
                   
                 LAKLMLNSLYGKFASNPDVT 
               
               
                   
                   
                 GKVPYLKENGALGFRLGEEE 
               
               
                   
                   
                 TKDPVYTPMGVFITAWGRYT 
               
               
                   
                   
                 TITAAQACYDRIIYCDTDSI 
               
               
                   
                   
                 HLTGTKIPDVIKDIVHPKKL 
               
               
                   
                   
                 GYWEHESTFKRAKYLRQKTY 
               
               
                   
                   
                 IQDIYMKRVKGYLVQGSPDD 
               
               
                   
                   
                 YTDIKFSVKCAGMTDKIKKE 
               
               
                   
                   
                 VTFENFKVGFSRKMKPKPVQ 
               
               
                   
                   
                 VPGGVVLVDSVFTIK 
               
               
                   
               
               
                   
                 125 
                 MKHMPRKMYSCDFETTTKVE 
               
               
                   
                 Phi29.K138Q_L142K_Y 
                 DCRVWAYGYMNIEDHSEYKI 
               
               
                   
                 224K_E239G_V250I_L2 
                 GNSLDEFMAWVLKVQADLYF 
               
               
                   
                 53A_R306Q_R308L_E3 
                 HNLKFDGAFIINWLERNGFK 
               
               
                   
                 75Y_A437G_E466K_D4 
                 WSADGLPNTYNTIISRMGQW 
               
               
                   
                 76H_A484E_E508R_D5 
                 YMIDICLGYKGKRKIHTVIY 
               
               
                   
                 10K_K512Y_E515Q_D5 
                 DSLKKLPFPVKKIAKDFQLT 
               
               
                   
                 70S_T571V 
                 VKKGDIDYHKERPVGYKITP 
               
               
                   
                   
                 EEYAYIKNDIQIIAEALLIQ 
               
               
                   
                   
                 FKQGLDRMTAGSDSLKGFKD 
               
               
                   
                   
                 IITTKKFKKVFPTLSLGLDK 
               
               
                   
                   
                 EVRKAYRGGFTWLNDRFKGK 
               
               
                   
                   
                 EIGEGMVFDINSAYPAQMYS 
               
               
                   
                   
                 RLLPYGEPIVFEGKYVWDED 
               
               
                   
                   
                 YPLHIQHIRCEFELKEGYIP 
               
               
                   
                   
                 TIQIKQSLFYKGNEYLKSSG 
               
               
                   
                   
                 GEIADLWLSNVDLELMKEHY 
               
               
                   
                   
                 DLYNVEYISGLKFKATTGLF 
               
               
                   
                   
                 KDFIDKWTYIKTTSYGAIKQ 
               
               
                   
                   
                 LAKLMLNSLYGKFASNPDVT 
               
               
                   
                   
                 GKVPYLKENGALGFRLGEEE 
               
               
                   
                   
                 TKDPVYTPMGVFITAWGRYT 
               
               
                   
                   
                 TITAAQACYDRIIYCDTDSI 
               
               
                   
                   
                 HLTGTKIPDVIKDIVHPKKL 
               
               
                   
                   
                 GYWEHESTFKRAKYLRQKTY 
               
               
                   
                   
                 IQDIYMKRVKGYLVQGSPDD 
               
               
                   
                   
                 YTDIKFSVKCAGMTDKIKKE 
               
               
                   
                   
                 VTFENFKVGFSRKMKPKPVQ 
               
               
                   
                   
                 VPGGVVLVDSVFTIK 
               
               
                   
               
               
                   
                 126 
                 MKHMPRKMYSCDFETTTKVE 
               
               
                   
                 Phi29.K135Q_L142K_Y 
                 DCRVWAYGYMNIEDHSEYKI 
               
               
                   
                 224K_E239G_V250I_L2 
                 GNSLDEFMAWVLKVQADLYF 
               
               
                   
                 53A_R306Q_R308L_E3 
                 HNLKFDGAFIINWLERNGFK 
               
               
                   
                 75Y_A437G_E466K_D4 
                 WSADGLPNTYNTIISRMGQW 
               
               
                   
                 76H_A484E_E508R_D5 
                 YMIDICLGYKGKRKIHTVIY 
               
               
                   
                 10R_K512Y_E515Q_K5 
                 DSLKKLPFPVKKIAQDFKLT 
               
               
                   
                 39E_D570S_T571V 
                 VKKGDIDYHKERPVGYKITP 
               
               
                   
                   
                 EEYAYIKNDIQIIAEALLIQ 
               
               
                   
                   
                 FKQGLDRMTAGSDSLKGFKD 
               
               
                   
                   
                 IITTKKFKKVFPTLSLGLDK 
               
               
                   
                   
                 EVRKAYRGGFTWLNDRFKGK 
               
               
                   
                   
                 EIGEGMVFDINSAYPAQMYS 
               
               
                   
                   
                 RLLPYGEPIVFEGKYVWDED 
               
               
                   
                   
                 YPLHIQHIRCEFELKEGYIP 
               
               
                   
                   
                 TIQIKQSLFYKGNEYLKSSG 
               
               
                   
                   
                 GEIADLWLSNVDLELMKEHY 
               
               
                   
                   
                 DLYNVEYISGLKFKATTGLF 
               
               
                   
                   
                 KDFIDKWTYIKTTSYGAIKQ 
               
               
                   
                   
                 LAKLMLNSLYGKFASNPDVT 
               
               
                   
                   
                 GKVPYLKENGALGFRLGEEE 
               
               
                   
                   
                 TKDPVYTPMGVFITAWGRYT 
               
               
                   
                   
                 TITAAQACYDRHYCDTDSIH 
               
               
                   
                   
                 LTGTKIPDVIKDIVHPKKLG 
               
               
                   
                   
                 YWEHESTFKRAKYLRQKTYI 
               
               
                   
                   
                 QDIYMKRVRGYLVQGSPDDY 
               
               
                   
                   
                 TDIKFSVKCAGMTDKIKEEV 
               
               
                   
                   
                 TFENFKVGFSRKMKPKPVQV 
               
               
                   
                   
                 PGGVVLVDSVFTIK 
               
               
                   
               
               
                   
                 127 
                 MKHMPRKMYSCDFETTTKVE 
               
               
                   
                 Phi29.K131E_K135Q_L 
                 DCRVWAYGYMNIEDHSEYKI 
               
               
                   
                 142K_Y224K_E239G_V 
                 GNSLDEFMAWVLKVQADLYF 
               
               
                   
                 250I_L253A_E375Y_A4 
                 HNLKFDGAFIINWLERNGFK 
               
               
                   
                 37G_D476H_A484E_E5 
                 WSADGLPNTYNTIISRMGQW 
               
               
                   
                 08R_D510K_K512Y_E5 
                 YMIDICLGYKGKRKIHTVIY 
               
               
                   
                 15Q_D523R_D570S_T5 
                 DSLKKLPFPVEKIAQDFKLT 
               
               
                   
                 71V 
                 VKKGDIDYHKERPVGYKITP 
               
               
                   
                   
                 EEYAYIKNDIQIIAEALLIQ 
               
               
                   
                   
                 FKQGLDRMTAGSDSLKGFKD 
               
               
                   
                   
                 IITTKKFKKVFPTLSLGLDK 
               
               
                   
                   
                 EVRKAYRGGFTWLNDRFKGK 
               
               
                   
                   
                 EIGEGMVFDINSAYPAQMYS 
               
               
                   
                   
                 RLLPYGEPIVFEGKYVWDED 
               
               
                   
                   
                 YPLHIQHIRCEFELKEGYIP 
               
               
                   
                   
                 TIQIKRSRFYKGNEYLKSSG 
               
               
                   
                   
                 GEIADLWLSNVDLELMKEHY 
               
               
                   
                   
                 DLYNVEYISGLKFKATTGLF 
               
               
                   
                   
                 KDFIDKWTYIKTTSYGAIKQ 
               
               
                   
                   
                 LAKLMLNSLYGKFASNPDVT 
               
               
                   
                   
                 GKVPYLKENGALGFRLGEEE 
               
               
                   
                   
                 TKDPVYTPMGVFITAWGRYT 
               
               
                   
                   
                 TITAAQACYDRIIYCDTDSI 
               
               
                   
                   
                 HLTGTEIPDVIKDIVHPKKL 
               
               
                   
                   
                 GYWEHESTFKRAKYLRQKTY 
               
               
                   
                   
                 IQDIYMKRVKGYLVQGSPDD 
               
               
                   
                   
                 YTRIKFSVKCAGMTDKIKKE 
               
               
                   
                   
                 VTFENFKVGFSRKMKPKPVQ 
               
               
                   
                   
                 VPGGVVLVDSVFTIK 
               
               
                   
               
               
                   
                 128 
                 MKHMPRKMYSCDFETTTKVE 
               
               
                   
                 Phi29.L142K_Y224K_E 
                 DCRVWAYGYMNIEDHSEYKI 
               
               
                   
                 239G_V250I_L253A_R3 
                 GNSLDEFMAWVLKVQADLYF 
               
               
                   
                 06Q_R308L_E375Y_A4 
                 HNLKFDGAFIINWLERNGFK 
               
               
                   
                 37G_E466K_D476H_A4 
                 WSADGLPNTYNTIISRMGQW 
               
               
                   
                 84E_E508R_D510K_K5 
                 YMIDICLGYKGKRKIHTVIY 
               
               
                   
                 12Y_E515Q_D570M 
                 DSLKKLPFPVKKIAKDFKLT 
               
               
                   
                   
                 VKKGDIDYHKERPVGYKITP 
               
               
                   
                   
                 EEYAYIKNDIQIIAEALLIQ 
               
               
                   
                   
                 FKQGLDRMTAGSDSLKGFKD 
               
               
                   
                   
                 IITTKKFKKVFPTLSLGLDK 
               
               
                   
                   
                 EVRKAYRGGFTWLNDRFKGK 
               
               
                   
                   
                 EIGEGMVFDINSAYPAQMYS 
               
               
                   
                   
                 RLLPYGEPIVFEGKYVWDED 
               
               
                   
                   
                 YPLHIQHIRCEFELKEGYIP 
               
               
                   
                   
                 TIQIKQSLFYKGNEYLKSSG 
               
               
                   
                   
                 GEIADLWLSNVDLELMKEHY 
               
               
                   
                   
                 DLYNVEYISGLKFKATTGLF 
               
               
                   
                   
                 KDFIDKWTYIKTTSYGAIKQ 
               
               
                   
                   
                 LAKLMLNSLYGKFASNPDVT 
               
               
                   
                   
                 GKVPYLKENGALGFRLGEEE 
               
               
                   
                   
                 TKDPVYTPMGVFITAWGRYT 
               
               
                   
                   
                 TITAAQACYDRIIYCDTDSI 
               
               
                   
                   
                 HLTGTKIPDVIKDIVHPKKL 
               
               
                   
                   
                 GYWEHESTFKRAKYLRQKTY 
               
               
                   
                   
                 IQDIYMKRVKGYLVQGSPDD 
               
               
                   
                   
                 YTDIKFSVKCAGMTDKIKKE 
               
               
                   
                   
                 VTFENFKVGFSRKMKPKPVQ 
               
               
                   
                   
                 VPGGVVLVDMTFTIK 
               
               
                   
               
            
           
         
       
     
     Additional exemplary polymerase mutations and/or combinations thereof are provided in  FIG. 7 . Such polymerases can be employed, e.g., in nucleic acid amplification, including, e.g., single molecule sequencing. Further exemplary polymerase mutations and/or combinations thereof are provided in  FIG. 8 . Such polymerases can be employed, e.g., in nucleic acid amplification, including, e.g., whole genome amplification. Additional exemplary polymerase mutations and/or combinations thereof are provided in  FIG. 9 . Such polymerases can be employed, e.g., in nucleic acid amplification, including, e.g., single molecule sequencing using large (e.g., protein shield analogs, other shielded analogs, or other analogs with a molecular weight of at least 10,000) analogs. In  FIGS. 7-9 , positions of the mutations are identified relative to a wild-type D29 DNA polymerase (SEQ ID NO:1) where the name of the polymerase includes “Phi29,” and where the name of the polymerase includes “M2” positions are identified relative to a wild-type M2Y polymerase (SEQ ID NO:2). Numbers with a decimal point represent insertions; for example, 96.1 represents an insertion between positions 96 and 97. Where the feature “topo V fusion” is listed, it indicates that the polymerase includes a fusion as described in de Vega et al. (2010) “Improvement of φ29 DNA polymerase amplification performance by fusion of DNA binding motifs” Proc Natl Acad Sci USA 107:16506-16511. Additional features are listed in Table 11. The notation “pET16.BtagV7co.His10co,” where the tags are listing in the N-terminal position, indicates that the polymerase includes N-terminal His10 and biotin tags. The feature “Cterm_His10co” is the same as listing the His10 in the C terminal position; both terms indicate that the polymerase includes a C-terminal His10 tag. “pET16” or “pET11” refers to a vector used to produce a recombinant Φ29 polymerase comprising the indicated mutations, and “co” indicates that the polynucleotide sequence encoding certain features (e.g., a His10 tag or BtagV7) has been codon optimized; neither notation is relevant to the structure of the polymerase. 
     
       
         
           
               
             
               
                 TABLE 11 
               
             
            
               
                   
               
               
                 Exemplary exogenous features (e.g., tags, 
               
               
                 linkers, fusion domains, and the like) 
               
               
                 that are optionally present in polymerases 
               
               
                 of the invention. As noted above, polymerases 
               
               
                 of the invention can include any of these 
               
               
                 features alone or in combination with one 
               
               
                 or more additional features, typically at 
               
               
                 the N-terminal and/or C-terminal regions 
               
               
                 of the polymerase. Note that the initial 
               
               
                 glycine residue shown for the 
               
               
                 polyhistidine tag is optional. 
               
            
           
           
               
               
               
            
               
                   
                 Feature 
                 Sequence 
               
               
                   
               
               
                   
                 576GTSGA (linker 
                 GTSGA 
               
               
                   
                 amino acid 
                   
               
               
                   
                 sequence); 
                   
               
               
                   
                 SEQ ID NO: 47 
                   
               
               
                   
               
               
                   
                 GGGSGGGSGGGS (linker 
                 GGGSGGGSGGGS 
               
               
                   
                 sequence); 
                   
               
               
                   
                 SEQ ID NO: 48 
                   
               
               
                   
               
               
                   
                 GGG (linker sequence) 
                 GGG 
               
               
                   
               
               
                   
                 GGGS (linker sequence); 
                 GGGS 
               
               
                   
                 SEQ ID 
                   
               
               
                   
                 NO: 49 
                   
               
               
                   
               
               
                   
                 GGGSGGGS 
                 GGGSGGGS 
               
               
                   
                 (linker sequence); 
                   
               
               
                   
                 SEQ ID NO: 50 
                   
               
               
                   
               
               
                   
                 GGGSGGGSGGGSGGGS (linker 
                 GGGSGGGSGGGSGGGS 
               
               
                   
                 sequence); SEQ ID NO: 51 
                   
               
               
                   
               
               
                   
                 DYKDDDDK (protease site); 
                 DYKDDDDK 
               
               
                   
                 SEQ ID NO: 52 
                   
               
               
                   
               
               
                   
                 LEVLFQGP (protease site); 
                 LEVLFQGP 
               
               
                   
                 SEQ ID NO: 53 
                   
               
               
                   
               
               
                   
                 ENLYFQG (protease site); 
                 ENLYFQG 
               
               
                   
                 SEQ ID NO: 54 
                   
               
               
                   
               
               
                   
                 pET16.BtagV7co.Hisl0co 
                 MSVDGLNDFFEAQKI 
               
               
                   
                 (N-terminal B tag, 
                 EWHEAMGHHHHHHHH 
               
               
                   
                 His tag and 
                 HHSSGHIEGRH 
               
               
                   
                 linkers cloned into pET16); 
                   
               
               
                   
                 SEQ ID NO: 55 
                   
               
               
                   
               
               
                   
                 G.His10co.GGGSGGGSGGGS.Bta 
                 GHHHHHHHHHHGGGS 
               
               
                   
                 gV7co or His10co.GGGSGGGSG 
                 GGGSGGGSGLNDFFE 
               
               
                   
                 GGS.BtagV7co 
                 AQKIEWHE 
               
               
                   
                 (C-terminal tags and 
                   
               
               
                   
                 linkers in polymerases 
                   
               
               
                   
                 encoded in 
                   
               
               
                   
                 pETl 1 vectors); 
                   
               
               
                   
                 SEQ ID NO: 56 
                   
               
               
                   
               
               
                   
                 G.His10co or His10co 
                 GHHHHHHHHHH 
               
               
                   
                 (10 histidines 
                   
               
               
                   
                 preceded by a single 
                   
               
               
                   
                 amino acid glycine 
                   
               
               
                   
                 linker; inclusion of the 
                   
               
               
                   
                 glycine is optional); 
                   
               
               
                   
                 SEQ ID NO: 57 
                   
               
               
                   
               
               
                   
                 MeCP2(77-167)co 
                 (M)ASASPKQRRSIIR 
               
               
                   
                 (a portion of 
                 DRGPMYDDPTLPEGWT 
               
               
                   
                 MeCpG binding 
                 RKLKQRKSGRSAGKYD 
               
               
                   
                 protein 2; 
                 VYLINPQGKAFRSKV 
               
               
                   
                 the N-terminal 
                 ELIMYFEKVGDTSLD 
               
               
                   
                 methionine 
                 PNDFDFTVTGRGSPS 
               
               
                   
                 is included in 
                 R 
               
               
                   
                 cases where 
                   
               
               
                   
                 this is at the very 
                   
               
               
                   
                 beginning of the 
                   
               
               
                   
                 polypeptide chain); 
                   
               
               
                   
                 SEQ ID NO: 58 
                   
               
               
                   
               
               
                   
                 UL42C-delta320.co 
                 LPRRLHLEPAFLPYS 
               
               
                   
                 (HSV UL42 construct); 
                 VKAHECCMTDSPGGV 
               
               
                   
                 SEQ ID NO: 59 
                 APASPVEDASDASLG 
               
               
                   
                   
                 QPEEGAPCQVVLQGA 
               
               
                   
                   
                 ELNGILQAFAPLRTS 
               
               
                   
                   
                 LLDSLLVMGDRGILI 
               
               
                   
                   
                 HNTIFGEQVFLPLEH 
               
               
                   
                   
                 SQFSRYRWRGPTAAF 
               
               
                   
                   
                 LSLVDQKRSLLSVFR 
               
               
                   
                   
                 ANQYPDLRRVELAIT 
               
               
                   
                   
                 GQAPFRTLVQRIWTT 
               
               
                   
                   
                 TSDGEAVELASETLM 
               
               
                   
                   
                 KRELTSFVVLVPQGT 
               
               
                   
                   
                 PDVQLRLTRPQLTKV 
               
               
                   
                   
                 LNATGADSATPTTFE 
               
               
                   
                   
                 LGVNGKFSVFTTSTC 
               
               
                   
                   
                 VTFAAREEGVSSSTS 
               
               
                   
                   
                 TQVQILSNALTKAGQ 
               
               
                   
                   
                 AAANAKTVYGENTHR 
               
               
                   
                   
                 TFSVVVDDCSMRAVL 
               
               
                   
                   
                 RRLQVGGGTLKFFLT 
               
               
                   
                   
                 TPVPSLCVTATGPNA 
               
               
                   
                   
                 VSAVFLLKPQK 
               
               
                   
               
               
                   
                 SNAPtag 
                 MSVDMDKDCEMKRTT 
               
               
                   
                 (06-alkylguanine DNA 
                 LDSPLGKLELSGCEQ 
               
               
                   
                 alkyl transferase); 
                 GLHEIKLLGKGTSAA 
               
               
                   
                 SEQ ID NO: 60 
                 DAVEVPAPAAVLGGP 
               
               
                   
                   
                 EPLMQATAWLNAYFH 
               
               
                   
                   
                 QPEAIEEFPVPALHH 
               
               
                   
                   
                 PVFQQESFTRQVLWK 
               
               
                   
                   
                 LLKVVKFGEVISYQQ 
               
               
                   
                   
                 LAALAGNPAATAAVK 
               
               
                   
                   
                 TALSGNPVPILIPCH 
               
               
                   
                   
                 RVVSSSGAVGGYEGG 
               
               
                   
                   
                 LAVKEWLLAHEGHRL 
               
               
                   
                   
                 GKPGLGAM 
               
               
                   
               
               
                   
                 SetAndRingFinger 
                 (M)HMPANHFGPIPG 
               
               
                   
                 (SRA domain of 
                 VPVGTMWRFRVQVSE 
               
               
                   
                 mouse UHRF1; 
                 SGVHRPHVAGIHGRS 
               
               
                   
                 the N-terminal 
                 NDGAYSLVLAGGYED 
               
               
                   
                 methionine is 
                 DVDNGNYFTYTGSGG 
               
               
                   
                 included in cases 
                 RDLSGNKRTAGQSSD 
               
               
                   
                 where this is 
                 QKLTNNNRALALNCH 
               
               
                   
                 at the very beginning 
                 SPINEKGAEAEDWRQ 
               
               
                   
                 of the polypeptide 
                 GKPVRVVRNMKGGKH 
               
               
                   
                 APAEGNRYDGIY 
                 SKYKVVKYWPERGKS 
               
               
                   
                 chain); SEQ ID 
                 GFLVWRYLLRRDDTE 
               
               
                   
                 NO: 61 
                 PEPWTREGKDRTRQL 
               
               
                   
                   
                 GLTMQYPEGYLEALA 
               
               
                   
                   
                 NKEKSRKR 
               
               
                   
               
               
                   
                 DBJBP1.co 
                 TNLMVSTAVEKKKYL 
               
               
                   
                 (Thymine dioxygenase 
                 DSEFLLHCISAQLLD 
               
               
                   
                 JBP1 catalytic domain); 
                 MWKQARARWLELVGK 
               
               
                   
                 SEQ ID NO: 62 
                 EWAHMLALNPERKDF 
               
               
                   
                   
                 LWKNQSEMNSAFFDL 
               
               
                   
                   
                 CEVGKQVMLGLLGKE 
               
               
                   
                   
                 VALPKEEQAFWIMYA 
               
               
                   
                   
                 VHLSAACAEELHMPE 
               
               
                   
                   
                 VAMSLRKLNVKLKDF 
               
               
                   
                   
                 NFGGTRYFKDMPPEE 
               
               
                   
                   
                 KKRRMERKQRIEEAR 
               
               
                   
                   
                 RHGMP 
               
               
                   
               
               
                   
                 MBP (Maltose binding 
                 KIEEGKLVIWINGDK 
               
               
                   
                 Fusion protein); 
                 GYNGLAEVGKKFEKD 
               
               
                   
                 SEQ ID NO: 63 
                 TGIKVTVEHPDKLEE 
               
               
                   
                   
                 KFPQVAATGDGPDII 
               
               
                   
                   
                 FWAHDRFGGYAQSGL 
               
               
                   
                   
                 LAEITPDKAFQDKLY 
               
               
                   
                   
                 PFTWDAVRYNGKLIA 
               
               
                   
                   
                 YPIAVEALSLIYNKD 
               
               
                   
                   
                 LLPNPPKTWEEIPAL 
               
               
                   
                   
                 DKELKAKGKSALMFN 
               
               
                   
                   
                 LQEPYFTWPLIAADG 
               
               
                   
                   
                 GYAFKYENGKYDIKD 
               
               
                   
                   
                 VGVDNAGAKAGLTFL 
               
               
                   
                   
                 VDLIKNKHMNADTDY 
               
               
                   
                   
                 SIAEAAFNKGETAMTI 
               
               
                   
                   
                 NGPWAWSNIDTSKVN 
               
               
                   
                   
                 YGVTVLPTFKGQPSK 
               
               
                   
                   
                 PFVGVLSAGINAASP 
               
               
                   
                   
                 NKELAKEFLENYLLT 
               
               
                   
                   
                 DEGLEAVNKDKPLGA 
               
               
                   
                   
                 VALKSYEEELAKDPR 
               
               
                   
                   
                 IAATMENAQKGEIMP 
               
               
                   
                   
                 NIPQMSAFWYAVRTA 
               
               
                   
                   
                 VINAASGRQTVDEAL 
               
               
                   
                   
                 KDAQTRITK 
               
               
                   
               
            
           
         
       
     
     The mutations or combinations of mutations shown in  FIGS. 7-9  are not limited to use in a Φ29 or M2Y polymerase. Essentially any of these mutations, any combination of these mutations, and/or any combination of these mutations with the other mutations disclosed or referenced herein can be introduced into a polymerase (e.g., a Φ29-type polymerase) to produce a modified recombinant polymerase in accordance with the invention. Polymerases of the invention including the mutations or combinations provided in  FIGS. 7-9  can include any exogenous or heterologous feature (or combination of such features), e.g., at the N- and/or C-terminal region. Similarly, some or all of the exogenous features listed in  FIGS. 7-9  can be omitted, or substituted or combined with any of the other exogenous features described herein, and still result in a polymerase of the invention. As will be appreciated, the numbering of amino acid residues is with respect to a particular reference polymerase, such as the wild-type sequence of the Φ29 polymerase (SEQ ID NO:1) or M2Y polymerase (SEQ ID NO:2); actual position of a mutation within a molecule of the invention may vary based upon the nature of the various modifications that the enzyme includes relative to the wild type Φ29 enzyme, e.g., deletions and/or additions to the molecule, either at the termini or within the molecule itself. 
     EXAMPLES 
     It is understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application and scope of the appended claims. Accordingly, the following examples are offered to illustrate, but not to limit, the claimed invention. 
     Example 1 
     Characterization of Exemplary Recombinant Polymerases in Single Molecule Sequencing Reactions 
     Recombinant polymerases based on Φ29 or M2Y polymerase and including various combinations of mutations were expressed and purified as described below. The polymerases were characterized by use in single molecule sequencing. Single molecule sequencing data was obtained with recombinant Φ29 and M2Y polymerases including the mutation combinations listed in  FIG. 7 . Exemplary data are presented in Table 12. Data for each polymerase is presented along with data for a control polymerase, acquired from the same chip for comparison. nReads represents the number of ZMWs from which single molecule sequencing data was obtained. Accuracy and readlength are determined using data for those reads meeting selected performance criteria. 
     
       
         
           
               
             
               
                 TABLE 12 
               
             
            
               
                   
               
               
                 Single molecule sequencing with the exemplary recombinant 
               
               
                 Φ29 and M2Y polymerases listed in Tables 3-5. 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                   
                 Median 
                 Median 
                   
                   
                 Control 
                 Control 
               
               
                   
                   
                 Read 
                 Accuracy 
                 Control 
                 Control 
                 Median 
                 Median% 
               
               
                 Pol. a   
                 nReads 
                 lenqth b   
                 (%) 
                 Pol. c   
                 nReads 
                 Readlength b   
                 Accuracy 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                  7 e   
                 82 
                 1371.5 
                 86 
                 C1 
                 199 
                 1189 
                 85 
               
               
                   
               
               
                  8 e   
                 420 
                 1246.5 
                 85 
                 C2 
                 162 
                 964 
                 86 
               
               
                   
               
               
                  9 e   
                 118 
                 1285.5 
                 86 
                 C3 
                 237 
                 1143 
                 86 
               
               
                   
               
               
                 10 e   
                 151 
                 1045 
                 85 
                 C3 
                 234 
                 1020 
                 84 
               
               
                   
               
               
                 
                   lle 
                 
                 150 
                 934.5 
                 88 
                 C4 
                 177 
                 913 
                 88 
               
               
                   
               
               
                 12 e   
                 296 
                 505 
                 90 
                 C4 
                 247 
                 944 
                 89 
               
               
                   
               
               
                 13 e   
                 332 
                 871 
                 87 
                 C5 
                 152 
                 805 
                 86 
               
               
                   
               
               
                 14 e   
                 244 
                 792 
                 91 
                 C2 
                 260 
                 916.5 
                 91 
               
               
                   
               
               
                 15 e   
                 196 
                 766 
                 90 
                 C2 
                 95 
                 999 
                 90 
               
               
                   
               
               
                 16 f   
                 2973 
                 1970 
                 89 
                 C6 
                 2654 
                 1835 
                 88 
               
               
                   
               
               
                 17 e   
                 342 
                 1792 
                 81 
                 C3 
                 139 
                 1255 
                 86 
               
               
                   
               
               
                 18 d   
                 228 
                 1596 
                 86 
                 N/A 
                 N/A 
                 N/A 
                 N/A 
               
               
                   
               
               
                 19 f   
                 2393 
                 2227 
                 87 
                 C6 
                 2475 
                 2031 
                 87 
               
               
                   
               
               
                 20 e   
                 157 
                 994 
                 88 
                 C4 
                 198 
                 938.5 
                 89 
               
               
                   
               
               
                 21 f   
                 2001 
                 3048 
                 86 
                 C7 
                 2284 
                 2561 
                 85 
               
               
                   
               
               
                 22 e   
                 409 
                 1011 
                 88 
                 C4 
                 196 
                 966 
                 89 
               
               
                   
               
               
                 23 e   
                 101 
                 247 
                 89 
                 C2 
                 359 
                 1267 
                 90 
               
               
                   
               
               
                 24 e   
                 117 
                 483 
                 87 
                 C4 
                 213 
                 967 
                 88 
               
               
                   
               
               
                 25 e   
                 190 
                 405.5 
                 85 
                 C2 
                 139 
                 1204 
                 87 
               
               
                   
               
               
                 26 e   
                 381 
                 744 
                 90 
                 C2 
                 129 
                 1278 
                 90 
               
               
                   
               
               
                   a SEQ ID NO of exemplary polymerase (see Table 5). 
               
               
                   b Median readlength in nucleotides. 
               
               
                   c Control polymerases are 
               
               
                 C1: Φ29 K131E L142K Y148I Y224K D235E E239G V250A L253H E375Y A437G A484E E508R D510K K512Y E515Q His10 GGGSGGGSGGGS BtagV7, 
               
               
                 C2: Φ29 K131E Y224K E239G V250I L253A E375Y A437G A484E D510K K512Y E515Q His10 GGGSGGGSGGGS BtagV7, 
               
               
                 C3: Φ29 K131E Y148I Y224K D235E E239G L253H E375Y A437G A484E D510K K512Y E515Q His10 GGGSGGGSGGGS BtagV7, 
               
               
                 C4: Φ29 K131E Y148I Y224K E239G V250I L253A E375Y A437G A484E D510K K512Y E515Q His10 GGGSGGGSGGGS BtagV7, 
               
               
                 C5: M2Y Y145I E236G V247I L250A S253A E372Y A434G A481E D507K K509Y E512Q His10 GGGSGGGSGGGS BtagV7, 
               
               
                 C6: Φ29 Q99I K131E A134S Y224K E239G V250I L253A E375Y A437N A484E E508R D510K K512Y E515Q D570E His10 GGGSGGGSGGGS BtagV7, and 
               
               
                 C7: M2Y K128E Y145I E236G V247I L250A S253A E372Y A434G A481E D507K K509Y E512Q His10 GGGSGGGSGGGS BtagV7, where positions are identified relative to SEQ ID NO: 1 for C1-C4 and C6 and relative to SEQ ID NO: 2 for C5 and C1. 
               
               
                   d The polymerase/primer/template complex was immobilized on the ZMW bottom through a biotinylated primer rather than through a biotin tag on the polymerase as for the other nineteen polymerases in Table 12. No on-chip control polymerase was employed. Data obtained from 20 minute movie. 
               
               
                   e Data obtained from 7 minute movie. 
               
               
                   f Data obtained from 45 minute movie. 
               
            
           
         
       
     
     Materials and Methods 
     Molecular Cloning 
     The phi29 and M2Y polymerase genes were cloned into either pET16 or pET11 (Novagen). Primers for specified mutations are designed and introduced into the gene using the Phusion Hot Start DNA Polymerase Kit (New England Biolabs). A PCR reaction is performed to incorporate mutations and product is purified using ZR-96 DNA Clean and Concentration Kits (Zymo Research). PCR products are digested with NdeI/BamHI and ligated into the vector. Plasmids are transformed into TOP10  E. coli  competent cells, plated on selective media and incubated at 37° C. overnight. Colonies are selected and plasmid is purified using Qiagen miniprep kits. Plasmids are then sequenced (Sequetech). 
     Protein Purification 
     Plasmid containing the recombinant polymerase gene is transformed into BL21 Star21 CDE3+Biotin Ligase cells (Invitrogen) using heat shock. Transformed cells are grown in selective media overnight at 37° C. 200 μL of the overnight culture are diluted into 4 mL of Overnight Express Instant TB Medium (EMD Chemicals) supplemented with biotin, glycerol, and antibiotics and grown at 37° C. until controls reach O.D. value of 4-6. Cultures are then incubated at 18° C. for 16 hours. Following this incubation, cells are harvested, resuspended in lysis buffer, and frozen at −80° C. Cells are thawed. The resulting lysate is centrifuged and supernatant is collected. Polymerase is purified over nickel followed by heparin columns. The resulting proteins are run on gels and quantified by SYPRO® staining. 
     Single Molecule Sequencing 
     Enzymes are characterized by single molecule sequencing basically as described in Eid et al. (2009) Science 323:133-138 (including supplemental information), using reagents similar to those commercially available in SMRT™ sequencing kits (Pacific Biosciences of California, Inc.). Each enzyme is initially screened with a single 7 minute movie followed by secondary screening with 30 minute replicates where applicable, or with a single 20 or 45 minute movie. Data presented in Table 12 are from 7, 20, and 45 minute movies as indicated in the table. Enzymes are evaluated, e.g., based on readlength and accuracy compared to control enzymes. 
     Example 2 
     Characterization of Exemplary Recombinant Polymerases in Single Molecule Sequencing Reactions with Protein Shield Analogs 
     Recombinant polymerases based on Φ29 or M2Y polymerase and including various combinations of mutations were expressed and purified as described below. The polymerases were characterized by use in single molecule sequencing with a set of four protein shield nucleotide analogs. Single molecule sequencing data was obtained with recombinant Φ29 and M2Y polymerases including the mutation combinations listed in  FIG. 9 . Exemplary data are presented in Table 13. Data for each polymerase is presented along with data for a control polymerase, acquired from the same chip for comparison. nReads represents the number of ZMWs from which single molecule sequencing data was obtained. Accuracy, readlength, and other characteristics are determined using data for those reads meeting selected performance criteria. 
     
       
         
           
               
             
               
                 TABLE 13 
               
             
            
               
                   
               
               
                 Single molecule sequencing with exemplary recombinant Φ29 and M2Y 
               
               
                 polymerases listed in Tables 7-9. 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                   
                   
                   
                   
                   
                   
                 Ratio 
                   
                   
                   
               
               
                   
                   
                 Control 
                 Control 
                 Ratio 
                 Delta 
                 Global 
                 Ratio 
                 Ratio 
                 Delta 
               
               
                 Pol.  a   
                 nReads 
                 Pol.  b   
                 nReads 
                 RL  c   
                 Accur.  d   
                 Speed  e   
                 IPD  f   
                 PW  g   
                 Pause  h   
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                 67 
                 5441 
                 79 
                 4124 
                 1.21 
                 −0.01 
                 0.99 
                 0.96 
                 0.98 
                 −0.03 
               
               
                 68 
                 833 
                 79 
                 4124 
                 0.99 
                 0.01 
                 0.88 
                 1.07 
                 1.14 
                 −0.02 
               
               
                 69 
                 3666 
                 79 
                 2848 
                 1.43 
                 −0.02 
                 1.28 
                 0.63 
                 0.98 
                 −0.03 
               
               
                 70 
                 1453 
                 79 
                 1591 
                 1.41 
                 −0.01 
                 1.39 
                 0.62 
                 0.96 
                 0.01 
               
               
                 71 
                 1288 
                 79 
                 1591 
                 1.4 
                 −0.02 
                 1.43 
                 0.59 
                 0.97 
                 0.01 
               
               
                 72 
                 3510 
                 79 
                 1591 
                 1.43 
                 −0.01 
                 1.26 
                 0.74 
                 0.97 
                 0.02 
               
               
                 73 
                 3407 
                 79 
                 1591 
                 1.37 
                 −0.01 
                 1.22 
                 0.72 
                 0.98 
                 −0.01 
               
               
                 74 
                 4000 
                 79 
                 1501 
                 1.15 
                 −0.04 
                 0.95 
                 1.05 
                 0.89 
                 −0.03 
               
               
                 75 
                 2371 
                 68 
                 553 
                 1.16 
                 0 
                 1.12 
                 0.94 
                 0.97 
                 0.03 
               
               
                 76 
                 645 
                 68 
                 867 
                 1.14 
                 0.01 
                 0.96 
                 0.95 
                 1.06 
                 −0.03 
               
               
                 77 
                 584 
                 79 
                 2113 
                 1.06 
                 −0.01 
                 1.11 
                 0.80 
                 1.08 
                 −0.01 
               
               
                   
               
               
                   a  SEQ ID NO of exemplary polymerase (see Table 9). 
               
               
                   b  SEQ ID NO of control polymerase (see Table 9). 
               
               
                   c  Median readlength in nucleotides for the test polymerase divided by the median readlength for the control polymerase 
               
               
                   d  Median accuracy for the test polymerase minus the median accuracy for the control polymerase 
               
               
                   e  Polymerization rate observed for the test polymerase divided by the polymerization rate observed for the control polymerase 
               
               
                   f  The ratio (test polymerase/control polymerase) of the (top 10%) trimmed mean interpulse distance calculated for each base and averaged over the four bases 
               
               
                   g  The ratio (test polymerase/control polymerase) of the (top 5%) trimmed mean pulse width calculated for each base and averaged over the four bases 
               
               
                   h  [PolRate * (median(PW) + median(IPD))/ln(2)], calculated for the test polymerase minus that calculated for the control polymerase, where PolRate is the polymerization rate, PW is pulse width, and IPD is interpulse distance 
               
            
           
         
       
     
     Materials and Methods 
     Molecular Cloning 
     The phi29 and M2Y polymerase genes were cloned into either pET16 or pET11 (Novagen). Primers for specified mutations are designed and introduced into the gene using the Phusion Hot Start DNA Polymerase Kit (New England Biolabs). A PCR reaction is performed to incorporate mutations and product is purified using ZR-96 DNA Clean and Concentration Kits (Zymo Research). PCR products are digested with NdeI/BamHI and ligated into the vector. Plasmids are transformed into TOP10  E. coli  competent cells, plated on selective media and incubated at 37° C. overnight. Colonies are selected and plasmid is purified using Qiagen miniprep kits. Plasmids are then sequenced (Sequetech). 
     Protein Purification 
     Plasmid containing the recombinant polymerase gene is transformed into BL21 Star21 CDE3+Biotin Ligase cells (Invitrogen) using heat shock. Transformed cells are grown in selective media overnight at 37° C. 200 μL of the overnight culture are diluted into 4 mL of Overnight Express Instant TB Medium (EMD Chemicals) supplemented with biotin, glycerol, and antibiotics and grown at 37° C. until controls reach O.D. value of 4-6. Cultures are then incubated at 18° C. for 16 hours. Following this incubation, cells are harvested, resuspended in lysis buffer, and frozen at −80° C. Cells are thawed. The resulting lysate is centrifuged and supernatant is collected. Polymerase is purified over nickel followed by heparin columns. The resulting proteins are run on gels and quantified by SYPRO® staining. 
     Single Molecule Sequencing 
     Enzymes are characterized by single molecule sequencing on a PACBIO™ RS sequencing instrument using standard laser and analysis options, basically as described in Eid et al. (2009) Science 323:133-138 (including supplemental information) and Korlach et al. (2010) Methods in Enzymology 72:431-455, using a set of protein shield analogs with a structure similar to that shown in FIG. 23 of U.S. patent application Ser. No. 13/767,619 corresponding to bases A, G, C, and T. Each of the protein shield nucleotide analogs has 6 phospholinked nucleotide moieties linked to a streptavidin through a bis-biotin linker. Each of the nucleotide analogs has a different dye component. The T analog has a double dye moiety with an emission maximum of about 558 nm, the G analog has a FRET dye pair with an emission maximum of about 598 nm, the A analog has a single dye with an emission maximum of about 659 nm, and the C analog has a FRET dye pair with an emission maximum of about 697 nm. Other reagents are similar to those commercially available in SMRT™ C2 sequencing kits (Pacific Biosciences of California, Inc.) with the addition of 650 nM free streptavidin in the chip wash buffer. Each enzyme is screened with a single 90 minute movie. Enzymes are evaluated, e.g., based on readlength and accuracy compared to control enzymes. 
     While the foregoing invention has been described in some detail for purposes of clarity and understanding, it will be clear to one skilled in the art from a reading of this disclosure that various changes in form and detail can be made without departing from the true scope of the invention. For example, all the techniques and apparatus described above can be used in various combinations. All publications, patents, patent applications, and/or other documents cited in this application are incorporated by reference in their entirety for all purposes to the same extent as if each individual publication, patent, patent application, and/or other document were individually indicated to be incorporated by reference for all purposes.