bluuebunny/crossref_metadata_2025_split huggingface dataset:
Suppression of IIIGlc‐defects by Enzymes IINag and IIBgl of the PEP:carbohydrate phosphotransferase system
Authors: Vogler A. P. , Broekhuizen C. P. , Schuitema A. , Lengeler J. W. , Postma P. W. 
Published: October 2006

SummaryThe Enzymes II of the PEP:carbohydrate phosphotransferase system (PTS) specific for N‐acetylglucosamine (IINag) and β‐glucosides (IIBgl) contain C‐terminal domains that show homology with Enzyme IIIGlc of the PTS. We investigated whether one or both of the Enzymes II could substitute functionally for IIIGlc. The following results were obtained: (i) Enzyme IINag, synthesized from either a chromosomal or a plasmidencoded nagE+ gene could replace IIIGlc in glucose, methyl α‐glucoside and sucrose transport via the corresponding Enzymes II. An Enzyme IINag with a large deletion in the N‐terminal domain but with an intact C‐terminal domain could also replace IIIGlc in IIGlc‐dependent glucose transport, (ii) After decryptification of the Escherichia coli bgl operon, Enzyme IIBgl could substitute for IIIGlc. (iii) Phospho‐HPr‐dependent phosphorylation of methyl α‐glucoside via IINag/IIGlc is inhibited by antiserum against IIIGlc as is N‐acetyl‐glucosamine phosphorylation via IINag. (iv) In strains that contained the plasmid which coded for IINag, a protein band with a molecular weight of 62000 D could be detected with antiserum against IIIGlc. We conclude from these results that the IIIGlc‐like domain of Enzyme IINag and IIBgl can replace IIIGlc in IIIGlc‐dependent carbohydrate transport and phosphorylation.
Germination‐specific cortex‐lytic enzyme is activated during triggering of Bacillus megaterium KM spore germination
Authors: Foster S. J. , Johnstone K. 
Published: October 2006

SummaryAntibodies were raised against purified germinationspecific cortex‐lytic enzyme (GSLE) from spores of Bacillus megaterium KM which neutralized the ability of GSLE to germinate permeabilized spores. Western blotting of dormant spore and vegetative cell fractions separated by SDS‐PAGE demonstrated that GSLE is spore‐specific and that >90% of the GSLE is associated with the dormant spore cortex peptidoglycan as a phosphorylated 63 kD pro‐form, which could only be visualized after lysozyme digestion of the peptidoglycan. During germination, the 63 kD pro‐form of GSLE is processed to release the active enzyme, which had an apparent molecular weight of 30 kD. Inhibitor studies demonstrated that GSLE activation occurs as part of the commitment reaction and thus represents the first‐identified enzymatic event to occur during germination triggering. Proteins that cross‐react with anti‐GSLE sera are present in spore fractions of other species.
Phylogeny of metabolic pathways: O‐acetylserine sulphydrylase A is homologous to the tryptophan synthase beta subunit
Authors: Levy S. , Danchinl A. 
Published: October 2006

SummaryThe cysK gene of Escherichia coli K‐12 encoding O‐acetylserine sulphydrylase A, was cloned and its nucleotide sequence, together with that of the flanking regions, was determined. The deduced amino acid sequence of the carboxy‐terminal moiety of O‐acetylserine sulphydrylase A shows significant similarity to the amino acid sequence of tryptophan synthase beta chain from several organisms. This sequence similarity is likely to reflect the structural homologies of substrates shared by both enzymes. This may indicate that these proteins, although catalysing different reactions in different metabolic pathways, have evolved from a common ancestral gene.
Secretion and processing of the Bacillus subtilis endo‐β‐1,3‐1,4‐glucanase in Escherichia coli
Authors: Gormley E. P. , Cantwell B. A. , Barker P. J. , Gilmour R. S. , McConnell D. J. 
Published: October 2006

SummaryThe endo‐β‐1,3‐1,4‐glucanase enzyme of Bacillus subtilis C120, when synthesized in Escherichia coli, is located mainly in the cytoplasm, but enzyme activity is also detected in the periplasmic space and in the extracellular medium. The proportion recovered in the extracellular medium is not altered by changes in the levels of synthesis of the enzyme. Lysis of E. coli cells is ruled out as the cause of the secretion by the normal localization of β‐galactosidase, an intracellular protein. However, β‐lactamase, which is normally found in the periplasmic space, is detected in the extracellular medium of E. coli transformants containing β‐glucanase plasmids, suggesting that the presence of β‐glucanase in the cell alters the permeability of the outer membrane. The β‐glucanase proteins found in the extracellular medium, the periplasmic space and the cytoplasm have the same electrophoretic mobilities as the secreted enzyme of B. subtilis. Amino‐terminal sequencing has shown that the β‐glucanase enzyme in the intracellular fraction of E. coli is processed at a site two amino acids distant from the processing site used in B. subtilis.
Characterization of a protein inhibitor of extracellular proteases produced by Erwinia chrysanthemi
Authors: Létoffé S. , Delepelaire P. , Wandersman C. 
Published: October 2006

Summary Erwinia chrysanthemi, a phytopathogenic bacterium, produces a protease inhibitor which is a low‐molecu‐lar‐weight, heat‐stable protein. In addition to its action on the three E. chrysanthemi extracellular proteases A, B and C, it also strongly inhibits the 50 kD extracellu‐lar protease of Serratia marcescens. Its structural gene (inh) was subcloned and expressed in Escher‐ichia coli, in which it encodes an active inhibitor which was purified. The nucleotide sequence of the inh gene shows an open reading frame of 114 codons. The N‐terminal amino acid sequence of the purified inhibi‐tor was also determined. It indicated the existence of an amino‐terminal signal peptide absent from the mature protein. The inhibitor is entirely periplasmic in E. chrysanthemi and partially periplasmic in E. coli.
Transcription of rhiA, a gene on a Rhizobium leguminosarum bv. viciae Sym plasmid, requires rhiR and is repressed by flavanoids that induce nod genes
Authors: Economou A. , Hawkins F. K. , Downie J. A. , Johnston A. W. B. 
Published: October 2006

SummaryStrains of Rhizobium leguminosarum biovar viciae specifically make an abundant protein (Rhi) in free‐living culture but not in bacteroids. Genes needed for Rhi synthesis are on a Sym plasmid and here we show that one of these genes, rhiA, is the structural gene that specifies this polypeptide. Transcription of rhiA requires a regulatory gene, rhiR, located close to rhiA and to nod genes involved in nodulation. Mutations in rhiA or rhiR do not appear to affect symbiotic nitrogen fixation. Transcription of rhiA is repressed in cells grown in the presence of the flavanone hesperetin or the flavone apigenin, both of which are potent inducers of transcription of nod genes. This was deduced from the use of rhiA‐lacZ fusions; however, when the Rhi polypeptide was detected in SDS gels, there was no apparent difference in the intensity of its staining in extracts obtained from cells grown with or without these flavanoid nod gene inducer molecules. However, a mutation in a nodulation gene, nolR, also closely linked to the nod and rhi genes, caused a severe depression in the amount of Rhi (as seen on gels) that was made in cells grown in the presence of inducer flavanoids.
Cloning and characterization of NSP1, a locus encoding a component of a CDC25‐dependent, nutrient‐responsive pathway in Saccharomyces cerevisiae
Authors: Tripp M. L. , Bouchard R. A. , Pinon R. 
Published: October 2006

SummaryThe NSP1 gene in Saccharomyces cerevisiae has been identified by its ability, when expressed at high levels, to bypass the CDC25 requirement for growth. Sequence analysis of the cloned NSP1 locus suggests that the NSP1 product contains 269 amino acids and has a membrane‐spanning domain at its carboxyl terminus. The NSP1 protein does not have sequence similarity to other known proteins, and is not related to the CDC25 protein, or to any of the previously described suppressors of CDC25 mutants. Phosphoprotein analysis of NSP1‐suppressed cells indicates that the NSP1 product controls the phosphorylation of two 31 kD proteins whose phosphorylation and de‐phosphorylation are strongly correlated with cell‐cycle arrest and proliferation, respectively, and suggests that the NSP1 product is an important downstream element of a CDC25‐dependent, nutrient‐responsive, phosphorylation pathway.
Transcriptional regulation of ceil division genes in Escherichia coli
Authors: Dewar S. J. , Kagan‐Zur V. , Begg K. J. , Donachie W. D. 
Published: October 2006

SummaryThe complete Escherichia coli ftsQ coding sequence, together with part of the ftsA coding sequence, has been cloned upstream of the lacZ open reading frame in a λ‐vector (λJFL100). Cells which are lysogenic for λJFL100 transcribe the cloned lacZ from promoter(s) within the ftsQ and ftsA sequences. The level of β‐galactosidase produced is dependent on growth rate (and/or cell size) and Is derepressed in an ftsA‐deficient mutant. Transcription during the cell cycle is restricted to the time of cell division.
Location and molecular cloning of the structural gene for the deoxyguanosine triphosphate triphosphohydrolase of Escherichia coli
Authors: Quirk S. , Seto D. , Bhatnagar S. K. , Gauss P. , Gold L. , Bessman M. J. 
Published: October 2006

SummaryThe structural gene for deoxyguanosine triphosphate triphosphohydrolase (dGTPase) (EC 3.1.5.1) and its regulator, optA, have been located on a lambda phage carrying a 17.5kb Escherichia coli DNA insert. The DNA fragment has been excised and ligated into pBR325 and also transferred to another lambda vector. From the results of transduction and transformation experiments, we find that the structural gene for dGTPase is very closely linked to optA and dapD, which locates it at approximately 3.6 minutes on the genetic map of E. coli K12. We propose the mnemonic dgt as the designation for the structural gene for this enzyme.
Nucleotide sequence of the regulatory nifA gene of Rhizobium leguminosarum PRE: transcriptional control sites and expression in Escherichia coli
Authors: Roelvink P. W. , Hontelez J. G. J. , van Kammen A. , van den Bos R. C. 
Published: October 2006

SummaryWe report the sequence of the regulatory nifA gene of Rhizobium leguminosarum PRE. The transcription initiation and termination sites of nifA were mapped and a potential promoter and a rho‐independent terminator identified. The nifA gene has two possible translation start sites, both of which are used in an Escherichia coli background, resulting in proteins with apparent molecular weights of 58kD and 57kD; initiation at the second site is preferred over initiation at the first. The nifA‐nifB intergenic region contains an rpoN‐dependent promoter for the nifB gene but no consensus upstream activator sequence (UAS).A potential DNA‐binding domain, consisting of two α‐helices separated by a four‐amino‐acid linker, is located at the C‐terminal end of the NifA amino acid sequence.
Mammalian cell adhesion functions and cellular penetration of enteropathogenic Yersinia species
Authors: Isberg R. R. 
Published: October 2006

SummaryThe entry of enteropathogenic Yersinia into cultured mammalian ceils has been studied in order to gain insight into the mechanism of bacterial penetration into host cells during infection. There exist at least three pathways for entry by Yersinia into mammalian cells, the most efficient of which is promoted by invasin, the product of the inv gene. Invasin is an outer membrane protein that attaches to a mammalian cell receptor, initiating the entry process. Several receptors that bind invasin have been identified, and each is a member of the VLA family of integrin cell adhesion molecules. The role of integrins in the entry process is discussed, as is the ability of invasin to stimulate uptake by binding to its integrin receptor.
Phosphoribosylpyrophosphate (PRPP)‐less mutants of Escherichia coli
Authors: Hove‐Jensen B. 
Published: October 2006

SummaryA DNA fragment encoding kanamycin resistance was inserted in vitro into a plasmid‐borne prs gene encoding phosphoribosylpyrophosphate synthetase of Escherichia coli. The resulting plasmids were subsequently transferred to the chromosome by homologous recombination and the haploid strains prs‐3::KanR and prs‐4::KanR were obtained. These strains were fully viable, but required guanosine, uridine, histidine, tryptophan and nicotinamide mononucleotide. There was no phosphoribosylpyrophosphate synthetase activity or phosphoribosylpyrophosphate pool in the mutant strains. These results show that phosphoribosytpyrophosphate synthetase is dispensable for E. coli.
Mapping the surface regions of Pseudomonas aeruginosa PAK pilin: the importance of the C‐terminal region for adherence to human buccal epithelial cells
Authors: Lee K. K. , Doig P. , Irvin R. T. , Paranchych W. , Hodges R. S. 
Published: October 2006

SummaryThe adherence of non‐mucoid Pseudomonas aeruginosa strains is believed to be mediated by the pilus, which consists of a single protein subunit of 15000 Oaltons called pilin. Ten antipeptide antisera were raised to map the surface regions of pilin from P. aeruginosa strain K (PAK). Only one of the antipeptide antisera to the eight predicted surface regions failed to react with PAK pili in direct ELISA. Five out of eight synthetic peptides representing the eight predicted surface regions reacted with anti‐PAK pilus anti‐serum, indicating their surface exposure. Combining the antipeptide and antipilus antisera results, all eight predicted surface regions were demonstrated to be surface‐exposed. The PAK 128‐144‐OH peptide produced the best binding antiserum to PAK pili. Only antipeptide Fab fragments directed against the disulphide bridged C‐terminal region of PAK piiin blocked the adherence of pili to human buccal epithelial cells, which suggests that this region contains the receptor‐binding domain of the PAK pilus.
Cloning of a β‐tubulin gene from Plasmodium falciparum
Authors: Delves C. J. , Ridley R. G. , Goman M. , Holloway S. P. , Hyde J. E. , Scaife J. G. 
Published: October 2006

SummaryWe describe the isolation and characterization of a gene for β‐tubulin from the malaria parasite, Plasmodium falciparum. This organism appears to contain a single gene encoding β‐tubulin. A single transcript from this gene can be detected in the total RNA of the parasite's asexual blood stages. The complete sequence for the gene has been elucidated. It has two introns, one of which has a position identical to that of a related parasite, Toxoplasma gondii. The gene shows the usual preference for codons with A or T in the third position. The predicted amino acid sequence is compared with that of T. gondii and the human host. Further comparisons between these and fungal sequences of β‐tubulins resistant to benomyl, a drug binding this protein, highlight differences that could be exploited in the development of parasite‐specific anti‐tubulin drugs.
Characterization of the osmoregulated Escherichia coli proU promoter and identification of ProV as a membrane‐associated protein
Authors: May G. , Faatz E. , Lucht J. M. , Haardt M. , Bolliger M. , Bremer E. 
Published: October 2006

SummaryThe Escherichia coli proU operon encodes a high‐affinity, binding‐protein‐dependent transport system for the osmoprotectant glycine betaine. Expression of proU is osmoregulated, and transcription of this operon is greatly increased In cells grown at high osmolarity. Characterization of the proU operon and its promoter provided results similar to those published elsewhere (Gowrishankar, 1989; Stirling et al., 1989). The previously identified proU601 mutation, which leads to increased proU expression both at low‐and high osmolarity, is a G to A transition in the Pribnow box of the proU promoter, which increases the homology of the ‐10 region to the consensus sequence of E. coli promoters. Using an antiserum raised against a ProV‐β‐galactosidase hybrid protein, we have identified ProV as a protein associated with the cytoplasmic membrane. This cellular location is consistent with its proposed role as the energy ‐coupling component of the ProU transport system.
Specificity of Bacillus thuringiensis for lepidopteran larvae: factors involved in vivo and in the structure of a purified protoxin
Authors: Arvidson H. , Dunn P. E. , Strnad S. , Aronson A. I. 
Published: October 2006

SummaryThe relative LD50 values in two test Lepidoptera of Bacillus thuringiensis subspecies kurstaki HD1, which contains three crylA protoxin genes, was the same as a plasmid‐cured derivative or a Bacillus cereus transcipient containing only one of the three genes. Differential rates of transcription of these genes in the original strain could account, at least partly, for this result. Strains containing only the single protoxin gene (crylA(b)) produced inclusions when grown at 25°C but not 32°C, despite transcription of this gene at both temperatures. The instability of the crylA(b) protoxin was not found in the parental B. thuringiensis subsp. kurstaki HD1 strain grown at either temperature, however, so kurstaki HD1 strains with multiple protoxin genes must produce some stabilizing factor, perhaps another protoxin.The cryl protoxins contain a highly conserved carboxyl half which is proteolytically removed upon conversion to toxin. All of the protoxin cysteines are present in protease‐sensitive regions and they are oxidized in inclusions. Most of the disulphides appear to be essential for specificity since their reduction in the crylA(b) protoxin resulted in loss of selectivity for one of the test insects. This lack of specificity was also found for this protoxin produced by an Escherichia coli clone, probably because of the reducing conditions in these cells. Specificity was restored by reoxidation of the pure protoxin, by removal of the carboxyl half of oxidized protoxin with trypsin, or by subcloning of the toxin portion. The oxidized form of protoxins must be important for specificity, for the formation of crystalline inclusions, and probably for interactions required for the stabilization of some protoxins.
Cloning, expression and sequence analysis of the gene encoding the 120kD surface‐exposed protein of Rickettsia rickettsii
Authors: Gilmore R. D. , Joste N. , McDonald G. A. 
Published: October 2006

Summary Rickettsia rickettsii (R strain) genomic DNA was partially digested and cloned into the lambda expression vector gt11 generating a genomic clone bank. Trans‐formant plaques were screened with antisera generated against the 120 kiloDalton protein of R. rickettsii to detect those phage expressing the recombinant protein. The gene encoding the 120kD protein was localized to a 4.3 kilobase Sphl‐BamHl fragment from the recombinant phage and subcioned into pUC18 and pUC19. Full‐length expression of the recombinant protein was achieved with both orientations. The gene and flanking regions were sequenced. The p120 gene consists of 3900 base pairs coding for 1300 amino acids. A distinguishable promoter region was not identified, although there are several 5′ sequences that resemble classical prokaryotic promoters. Downstream of the termination codon for this gene lies a 726 base pair open reading frame on the opposite strand with the potential to encode a protein of approximately 27 kD. The identity of this putative gene product is unknown. The two open reading frames are separated by a 106 base pair intergenic region that consists of a stretch of dyad symmetry resembling rho‐independent transcriptional terminators.
Molecular cloning, nucleotide sequence and fine‐structural analysis of the Corynebacterium glutamicum fda gene: structural comparison of C. glutamicum fructose‐1,6‐biphosphate aldolase to class I and class II aldolases
Authors: von der Osten C. H. , Barbas C. F. , Wong C.‐H. , Sinskey A. J. 
Published: October 2006

SummaryThe Corynebacterium glutamicum fda gene encoding fructose‐ 1,6‐btphosphate (FBP) aldolase has been isolated by complementation of an Escherichia coli mutant. The nucleotide sequence of a 3371 bp chromosomal fragment containing the C. glutamicum fda gene was determined. The N‐terminal amino acid sequence of C. glutamicum FBP aldolase identified the correct initiation site for the fda gene, and a molecular weight of 37092 was predicted for the fda polypeptide. S1 nuclease mapping identified the transcriptional start site, and Northern hybridization analysis indicated that the fda gene encodes a single 1.3 kb transcript. The primary structure of C. glutamicum FBP aldolase shows strong homology to class 11 FBP aldolases. Conservation of primary structure was observed between class I and class II aldolases, but several residues essential for catalytic activity in class I aldolases were absent from class II aldolases.
Analysis of genes coding for the sialic acid‐binding adhesin and two other minor fimbrial subunits of the S‐fimbrial adhesin determinant of Escherichia coli
Authors: Schmoll T. , Hoschützky H. , Morschhäuser J. , Lottspeich F. , Jann K. , Hacker J. 
Published: October 2006

SummaryThe S fimbrial adhesin (Sfa) enables Escherichia coli to attach to sialic acid‐containing receptor molecules of eukaryotic cells. As previously reported, the genetic determinant coding for the Sfa of an E. coli O6 strain was cloned, the gene coding for the major fimbrial subunit was identified and sequenced and the S specific adhesin was detected. Here we present evidence that in addition to the major subunit protein SfaA three other minor subunit proteins, SfaG (17kD), SfaS (14 kD) and SfaH (31 kD) can be isolated from the S‐specific fimbrial adhesin complex. The genes coding for these minor subunits were identified, mutagenized separately and sequenced. Using haemagglutination tests, electron‐microscopy and quantitative ELISA assays with monoclonal anti‐SfaA and anti‐SfaS antibodies the functions of the minor subunits were determined. It was determined that SfaS is identical to the S‐specific adhesin, which also plays a role in determination of the degree of fimbriation of the cell. The minor subunit SfaH also had some influence on the level of fimbriation of the cell, while SfaG is necessary for full expression of S‐specific binding. It was further shown that the amino‐terminal protein sequence of the isolated SfaS protein was identical to the protein sequence calculated from the DNA sequence of the sfaS gene locus.
Molecular linkage of the nifl fix and nod gene regions in Rhixobium leguminosarum biovear trifolii
Authors: Iismaa S. E. , Ealing P. M. , Scott K. F. , Watson J. M. 
Published: October 2006

SummaryNucleotide sequence analysis of a 2.5kb region downstream of the nifA gene from Rhizobium leguminosarum biovar trifolii has resulted in linkage, at the DNA sequence level, of the nifEN, nifHDK, fixABCX, nifA gene cluster with the nodEF, nodD, nodABCIJ genes. Four genes have been identified within this intervening region. Immediately 3’to the nifA gene is the nifB gene and the nifB‐linked ferredoxin‐encoding fdxN gene. Downstream of fdxN in R. leguminosarum bv. trifolii and in Rhizobium meliloti, we have identified an open reading frame which has not been described previously and which we propose to designate fixU. Downstream of fixU in R. leguminosarum by. trifolii is a nod gene, nodT, which is contiguous with nodJ (B. Surin et al., manuscript in preparation). As a result of this study, the linkage relationships of 22 symbiotic genes spanning a 24 kb region of the symbiotic plasmid from R. leguminosarum bv. trifoiii are now known.