DNA fragment encoding a polypeptide having nitrile hydratase activity, a transformant containing the DNA fragment and a process for the production of amides using the transformant

Abstract: The present invention discloses the amino acid sequence and nucleotide sequence of the α- and β-subunits of two types of nitrile hydratase derived from Rhodococcus rhodochrous J-l. The DNA fragment encoding nitrile hydratase is inserted into an expression vector and the recombinant vector is used for transformation. The transformant contains multiple copies of the gene and can produce much higher levels of nitrile hydratase than conventionally used microorganisms.

Description: The present invention relates to a DNA fragment derived from Rhodococcus rhodochrous J-l and encoding a polypeptide having nitrile hydratase activity which hydrates nitriles to amides. The invention also relates to a recombinant DNA containing the above DNA fragment, and a transformant transformed with the recombinant DNA. The present invention further relates to a method of producing nitrile hydratase using the transformant and of amides using nitrile hydratase. Nitrile hydratase or nitrilase is known as an enzyme that hydrates nitriles to amides. Microorganisms that produce nitrile hydratase include those belonging to the genus Bacillus , the genus Bacteridium , the genus Micrococcus and the genus Brevibacterium (See, JP-B-62-21517/1989, USP No. 4,001,081), the genus Corynebacterium and the genus Nocardia (See, JP-B-56-17918/1981, USP No. 4,248,968), the genus Pseudomonas (See, JP-B-59-37951/1984, USP No. 4,637,982), the genus Rhodococcus , the genus Arthrobacter and the genus Microbacterium (See, JP-A-61-162193/1986, EP-A-0188316), and Rhodococcus rhodochrous (See, JP-A-2-470/1990, EP-A-0307926). Nitrile hydratase has been used to hydrate nitriles to amides. In the invention, microorganisms are engineered to contain multiple copies of a recombinant DNA encoding nitrile hydratase according to a recombinant DNA technology. The recombinant produces a remarkably high level of nitrile hydratase compared with conventionally used microorganisms. The present inventors previously disclosed a DNA fragment derived from Rhodococcus sp. N-774 (FERM BP-1936) which also encodes a polypeptide having nitrile hydratase activity (JP-A-2-119778/1988). In contrast, the present inventors utilizes a DNA fragment derived from Rhodococcus rhodochrous J-l for the production of nitrile hydratase. We isolated the gene encoding nitrile hydratase, inserted the gene into a suitable plasmid vector and transformed an appropriate host with the recombinant plasmid, thus successfully obtained the transformant producing nitrile hydratase which has high activity also on aromatic nitriles. The present invention relates to (1) a DNA (H) fragment encoding a polypeptide having nitrile hydratase activity, said polypeptide comprising the α (H) -subunit as defined in the Sequence Listing by SEQ ID: No. 1 and the β (H) -subunit as defined in the Sequence Listing by SEQ ID: No. 2; (2) a DNA (L) fragment encoding a polypeptide having nitrile hydratase activity, said polypeptide comprising the α (L) -subunit as defined in the Sequence Listing by SEQ ID: No. 3 and the β (L) -subunit as defined in the Sequence Listing by SEQ ID: No. 4; (3) the DNA (H) fragment of (1) which contains a nucleotide sequence encoding said α (H) - and β (H) -subunits, comprising the DNA sequence of the α (H) -subunit as defined in the Sequence Listing by SEQ ID: No. 5 and the DNA sequence of the β (H) -subunit as defined in the Sequence Listing by SEQ ID: No. 6; (4) the DNA (L) fragment of (2) which contains a nucleotide sequence encoding said α (L) - and β (L) -subunits, comprising the DNA sequence of the α (L) -subunit as defined in the Sequence Listing by SEQ ID: No. 7 and the DNA sequence of the β (L) subunit as defined in the Sequence Listing by SEQ ID: No. 8; (5) a recombinant DNA comprising the DNA (H) or the DNA (L) of (1)-(4) in a vector; (6) a transformant transformed with the recombinant DNA of (5); (7) a method for the production of nitrile hydratase which comprises culturing the transformant as described in (6) and recovering nitrile hydratase from the culture; (8) a method for the production of amides which comprises hydrating nitriles using nitrile hydratase as described in (7) to form amides; and (9) a method for the production of amides which comprises culturing the transformant as described in (6), and hydrating nitriles using the resultant culture, isolated bacterial cells, treated matter thereof, or a fixed material of them, to form amides. The present invention is described in detail as follows. The present invention is carried out by the steps (1)-(8): (1) Isolation and Purification of Nitrile Hydratase and Partial Amino Acid Sequencing of Nitrile Hydratase Two types of nitrile hydratase (designated as H type and L type, respectively) are isolated and purified from Rhodococcus rhodochrous J-1 (FERM BP-1478) and both enzymes are separated into α and β subunits using HPLC. N-Terminal amino acid sequence each of the subunits is determined and shown in the Sequence Listing by SEQ ID: Nos. 9-12. (2) Preparation of a DNA Probe for a Nitrile Hydratase Gene A DNA probe is prepared from JM105/pYUK121 (FERM BP-1937) as described in JP-A-2-119778/1990 due to the high degree of homology in the amino acid sequence between the nitrile hydratase β subunit of Rhodococcus sp. N-774 described in said Japanese Patent Official Gazette and those of Rhodococcus rhodochrous J-1. Plasmid pYUK121 containing nitrile hydratase gene derived from Rhodococcus sp. N-774 is prepared from a JM105/pYUK121 culture. pYUK121 DNA is digested with SphI and SalI. The SphI-SalI fragment contains the nitrile hydratase gene (shown in the Sequence Listing by SEQ ID: No. 13)of Rhodococcus sp. N-774. The DNA fragment is radiolabeled. (3) Detection of a DNA Segment Containing a Nitrile Hydratase Gene from the Chromosome of Rhodococcus rhodochrous J-1 Chromosomal DNA is prepared from a Rhodococcus rhodochrous J-1 culture. The chromosomal DNA is digested with restriction enzymes and hybridized to the probe described in (2) using the Southern hybridization method [Southern, E.M., J. Mol. Biol. 98, 503 (1975)]. Two DNA fragments of different lengths are screened. (4) Construction of a Recombinant Plasmid A recombinant plasmid is constructed by inserting the chromosomal DNA fragment as prepared in (3) into a plasmid vector. (5) Transformation and Screening for a Transformant Containing the Recombinant Plasmid Transformants are prepared using the recombinant plasmid as described in (4). The transformant containing the recombinant plasmid is selected using the probe as described in (2) according to the colony hybridization method [R. Bruce Wallace et. al., Nuc. Aci. Res. 9, 879 (1981)]. Additionally, the presence of the nitrile hydratase gene in the recombinant plasmid is confirmed using the Southern hybridization method. The plasmids thus selected are designated as pNHJ10H and pNHJ20L. (6) Isolation and Purification of Plasmid DNA and Construction of the Restriction Map Plasmid DNAs of pNHJ10H and pNHJ20L as prepared in (5) are isolated and purified. The restriction map of the DNAs is constructed (Fig. 1) to determine the region containing nitrile hydratase gene. (7) DNA Sequencing The extra segment of the inserted DNA fragment in pNHJ10H and pNHJ20L is excised using an appropriate restriction enzyme. The inserted DNA fragment is then used for sequencing. The nucleotide sequence of the DNA fragment (SEQ ID:Nos. 14, 15) reveals that it contains the sequence deduced from the amino acid sequence as described in (1). (8) Production of Nitrile Hydratase Using the Transformant and Conversion of Nitriles to Amides The transformant as described in (8) is cultured. The bacterial cells are mixed with nitriles, a substrate of nitrile hydratase, and amides are produced. Rhodococcus rhodochrous J-l was deposited with Fermentation Research Institute, Agency of Industrial Science and Technology, and was assigned the accession number FERM BP-1478. A transformant TGl/pNHJ10H containing pNHJ10H as described in (5) and a transformant TGl/pNHJ20L containing pNHJ20L as described in (5) were deposited with the above and assigned the accession number FERM BP-2777 and FERM BP-2778, respectively. Any vectors including a plasmid vector (e.g., pAT153, pMP9, pHC624, pKC7, etc.), a phage vector (e.g., λgtll (Toyobo), Charon 4A (Amersham), etc.) may be used. Enzymes which may be used include SphI, SalI, EcoRI, BamHI, SacI, and the like, which are commercially available (Takara Shuzo). Various hosts may be used for transformation including but not limited to E. coli JM105 and E. coli TGl. Culture media for the transformant are those ordinarily used in the art. Conversion of nitriles to amides is carried out using nitrile hydratase, crude nitrile hydratase, the culture of the transformant, the isolated bacterial cells or treated matter thereof, and the like, prepared from the culture of the transformant. Suitable nitriles in the invention include aromatic nitriles having 4-10 carbon atoms in the aromatic moiety and aliphatic nitriles having 2-6 carbon atoms, which are described in the European Patent Publication No. 0,307,926. Typical examples of the nitriles are 4-, 3- and 2-cyanopyridines, benzonitrile, 2,6-difluorobenzonitrile, 2-thiophene carbonitrile, 2-furonitrile, cyanopyrazine, acrylonitrile, methacrylonitrile, crotonitrile, acetonitrile and 3-hydroxypropionitrile. The present invention discloses the amino acid sequence and nucleotide sequence of the α- and β-subunits of two types of nitrile hydratase derived from Rhodococcus rhodochrous J-l. The DNA fragment encoding nitrile hydratase is inserted into an expression vector and the recombinant vector is used for transformation. The transformant contains multiple copies of the gene and can produce much higher levels of nitrile hydratase than conventionally used microorganisms. Fig. 1 shows restriction maps of recombinant plasmids, pNHJ10H and pNHJ20L. The present invention is illustrated by the following Example. The following abbreviations are used in the Example. TE: Tris-HCl (10 mM; pH 7.8), EDTA (1 mM, pH 8.0) TNE: Tris-HCl (50 mM; pH 8.0), EDTA (1 mM, pH 8.0), NaCl (50 mM) STE: Tris-HCl (50 mM; pH 8.0), EDTA (5 mM, pH 8.0), Sucrose (35 mM) 2×YT medium: 1.6% Trypton; 1.0% Yeast extract, 0.5% NaCl Example (1) Isolation and Purification of Nitrile Hydratase and Partial Amino Acid Sequencing of Nitrile Hydratase Rhodococcus rhodochrous J-1 was cultured in a medium (3 g/ℓ of yeast-extract, 0.5 g/ℓ of KH₂PO₄, 0.5 g/ℓ of K₂HPO₄, 0.5 g/ℓ of MgSO₄·4H₂O, 0.01 g/ℓ of CoCl₂, and 3 g/ℓ of crotonamide, pH 7.2) at 28°C for 80 hours. The bacterial cells were harvested. 50 g of the bacterial cells were disrupted and fractionated with ammonium sulfate. The sample was dialyzed and the dialysate was centrifuged. The supernatant was subjected to DEAE-Cellulofine chromatography, Phenyl-Sepharose chromatography, Sephadex G-150 chromatography and Octyl-Sepharose chromatography. Two fractions with enzyme activity were obtained and dialyzed. The dialysates were subjected to a high performance liquid chromatography using a reversed phase column (Senshu Pak VP-304-1251, Senshu Kagaku), and two respective subunits (α and β) were obtained. N-terminal amino acid sequence of α 1 (H) -, β 1 (H) -, α 1 (L) - and β 1 (L) -subunits was determined using an Applied Biosystems model 470A protein sequencer. The amino acid sequences are shown in the Sequence Listing by SEQ ID: Nos. 9-12. (2) Preparation of a DNA Probe for Nitrile Hydratase Gene E. coli JM105 (FERM BP-1937) containing pYUK121 was cultured in 100 ml of 2×YT medium containing 50 µg/ml of ampicillin at 30°C overnight (12 hours). The bacterial cells were harvested and TNE was added to the cells. The cell suspension was then centrifuged. 8 ml of STE and 10 mg of lysozyme were added to the pellet. The mixture was incubated at 0°C for five minutes followed by the addition of 4 ml of 0.25M EDTA. 2 ml of 10% SDS and 5 ml of 5M NaCl were then added to the mixture at room temperature. The resultant mixture was incubated at 0-4°C for three hours and then ultracentrifuged. 1/2 volume of 30% PEG 6000 was added to the supernatant. The mixture was incubated at 0-4°C overnight (12 hours) and centrifuged. TNE was added to the pellet to bring the volume to 7.5 ml and CsCl was then added to the suspension. The mixture was centrifuged to remove proteins. Then, 300-500 mg/ml of ethidium bromide was added to the supernatant. The mixture was transferred to a centrifuge tube. The tube was heat-sealed and then ultracentrifuged. cccDNA was extracted using a peristaltic pump. A bit more than equal amount of isopropyl alcohol saturated with water was added to the extract to rid of ethidium bromide. The sample was dialyzed against TE. About 3 ml of purified pYUK121 was obtained. pYUK121 DNA was digested with SphI and SalI, resulting in a 2.07 kb DNA fragment containing a nitrile hydratase gene derived from Rhodococcus sp. N-774. The fragment was radiolabeled with ³²P to produce a probe. The nucleotide sequence of the probe is shown in the Sequence Listing by SEQ ID: No. 13. (3) Preparation of a DNA Fragment Containing a Chromosomal Nitrile Hydratase Gene Rhodococcus rhodochrous J-l was cultured in 100 ml of a medium (10 g/ℓ of glucose, 0.5 g/ℓ of KH₂PO₄, 0.5 g/ℓ of K₂HPO₄, 0.5 g/ℓ of MgSO₄·7H₂O, 1 g/ℓ of yeast extract, 7.5 g/ℓ of peptone, 0.01 g/ℓ of CoCl₂, 7.5 g/ℓ of urea, 1% glycine or 0.2 µg/ml of ampicillin, 1 ℓ of water, pH 7.2). The bacterial cells were harvested and the pellet was washed with TNE. The pellet was then suspended in 10 ml of TE. 4 ml of 0.25M EDTA, 10-20 mg of lysozyme, 10-20 mg of achromoprotease and 10 ml of 10×SDS were added to the suspension. The suspension was incubated at 37°C for three hours. 15 ml of phenol was added to the suspension. The mixture was incubated at room temperature for 15 minutes and then centrifuged. The upper layer was removed, and 0.7 ml of 2.5M sodium acetate and diethyl ether were added to the supernatant. The mixture was centrifuged and the upper layer was discarded. Two volumes of ethanol were added to the bottom layer and DNA was removed with a glass rod. DNA was rinsed for five minutes each with TE:ethanol 2:8, 1:9, and 0:10 (v/v). DNA was then resuspended in 2-4 ml of TE (37°C). 10 µℓ of a mixture of RNase A and T₁ was added to the suspension and the mixture was incubated at 37°C. An equal amount of phenol was added to the mixture which was then centrifuged. More than equal amount of ether was added to the supernatant. The mixture was centrifuged again, and the upper layer was discarded and the bottom layer was saved. The bottom layer was dialyzed against 2 ℓ of TE containing a small amount of chloroform overnight and further dialyzed against fresh TE for 3-4 hours. 4 ml of crude chromosomal DNA was obtained. 10 µℓ of TE, 3 µℓ of reaction buffer (10×) and 2 µℓ of SacI were added to 15 µℓ of crude chromosomal DNA. The mixture was incubated at 37°C for an hour and electrophoresed on an agarose gel at 60 V for three hours. The Southern hybridization of chromosomal DNA was carried out using the probe as described in (2). About 6.0 kb and 9.4 kb fragments were found to show a strong hybridization. 15 µℓ of chromosomal DNA was digested with SacI and electrophoresed on an agarose gel, as described above. 6.0 kb and 9.4 kb DNA fragments were cut out from the gel and taken in three volumes each of 8M NaClO₄. After solubilization, each solution was dotted on GF/C (Whatman) filter paper (6 mm in diameter). Ten drops (≃100 µℓ) of TE containing 6M NaClO₄ and then ten drops (≃ 100 µℓ) of 95% ethanol were added to the filter paper. The paper was air-dried for 3 minutes and placed in 0.5 ml Eppendorf tube. 40 µℓ of TE was added to the tube and the whole was incubated at 47°C for 30 minutes. The tube was then centrifuged. About 40 µℓ of the supernatant was obtained which contained 6.0 kb and 9.4 kb DNA fragments containing a nitrile hydratase gene of chromosomal DNA. The method of inserting the 6.0 kb DNA fragment into a vector is described below. The same method is applied for the insertion of the 9.4 kb DNA fragment into a vector. (4) Insertion of the Chromosomal DNA Fragment into a Vector 10 µℓ of TE, 3 µℓ of reaction buffer (10×) and 2 µℓ of SacI were added to 10 µℓ of pUC19. The mixture was incubated at 30°C for an hour. 2 µℓ of 0.25M EDTA was added to the mixture to stop the reaction. Then,7 µℓ of 1M Tris-HCl (pH 9) and 3 µℓ of BAP (bacterial alkaline phosphatase) were added to the mixture. The mixture was incubated at 65°C for an hour. TE was then added to the mixture to make a total volume to 100 µℓ. The mixture was extracted 3× with an equal amount of phenol. An equal amount of ether was added to the extract. The bottom layer was removed and 10 µℓ of 3M sodium acetate and 250 µℓ of ethanol were added to the bottom layer. The mixture was incubated at -80°C for 30 minutes, centrifuged, dried, and resuspended in TE. 5 µℓ of pUC19 DNA thus obtained and 40 µℓ of the 6.0 kb DNA fragment as described in (3) were mixed. 6 µℓ of ligation buffer, 6 µℓ of ATP (6 mg/ml) and 3 µℓ of T4 DNA ligase were added to the mixture. The mixture was incubated at 4°C overnight (12 hours) to produce the recombinant plasmid containing the 6.0 kb DNA fragment encoding the desired enzyme in the SacI site of pUC19. (5) Transformation and Screening of Transformants E. coli TGl (Amersham) was inoculated into 10 ml of 2×YT medium and incubated at 37°C for 12 hours. After incubation, the resultant culture was added to fresh 2×YT medium to a concentration of 1%, and the mixture was incubated at 37°C for two hours. The culture was centrifuged and the pellet was suspended in 5 ml of cold 50 mM CaCl₂. The suspension was placed on ice for 40 minutes and then centrifuged. 0.25 ml of cold 50 mM CaCl₂ and 60 µℓ of the recombinant DNA as described in (4) were added to the pellet. The mixture was incubated at 0°C for 40 minutes, heat-shocked at 42°C for two minutes, placed on ice for five minutes, and added to 10 ml of 2×YT medium. The mixture was incubated at 37°C for 90 minutes with shaking, then centrifuged. The pellet was suspended in 1 ml of 2×YT medium, and two 10 µℓ aliquots of the suspension were plated on a 2×YT agar plate containing 50 µg/ml of ampicillin separately. The plate was incubated at 37°C. The colony grown on the plate was selected by the colony hybridization method: The colony was transferred to a nitrocellulose filter and digested. The DNA was fixed on the filter and hybridized to the probe as described in (2). The filter was autoradiographed and a recombinant colony was selected. Additionally, the presence of a nitrile hydratase gene in the transformant was confirmed according to the Southern hybridization method. (6) Isolation and Purification of Recombinant Plasmid and Construction of the Restriction Map of the Inserted DNA Fragments The transformant selected as described in (5) was grown in 100 ml of 2×YT medium containing 50 µg/ml of ampicillin at 37°C overnight (12 hours). The bacterial cells were harvested and TNE was added to the cells. The cells were collected again by centrifugation, and 8 ml of STE and 10 mg of lysozyme were added to the cells. The mixture was incubated at 0°C for five minutes. 4 ml of 0.25M EDTA, 2 ml of 10% SDS (at room temperature) and 5 ml of 5M NaCl were added to the mixture. The mixture was incubated at 0-4°C for three hours, and ultracentrifuged. 1/2 volume of 30% PEG 6000 was added to the supernatant. The mixture was incubated at 0-4°C overnight (12 hours) and centrifuged again. TNE was added to the pellet to bring the volume up to 7.5 ml. CsCl was added to the suspension to rid of proteins. Then, 300-500 mg/ml of ethidium bromide was added to the supernatant and the mixture was transferred to a centrifuge tube. The tube was heat-sealed and ultracentrifuged. cccDNA was removed using a peristaltic pump. A bit more than equal amount of isopropyl alcohol saturated with water was added to cccDNA to remove ethidium bromide. The DNA sample was dialyzed against TE, resulting in about 3 ml of purified recombinant DNA. The recombinant plasmid thus obtained containing a 6.7 kb DNA fragment was designated as pNHJ10H (The recombinant plasmid containing a 9.4 kb DNA fragment was designated as pNHJ20L). These plasmid DNAs were digested with EcoRI, BamHI, PstI, SacI and SalI. The restriction maps were constructed and are shown in Fig. 1. (7) DNA Sequencing The location of a nitrile hydratase gene in the DNA fragment of pNHJ10H was determined according to the restriction map constructed and to the Southern hybridization method. An extra segment in pNHJ10H was cleaved off with PstI and SalI: The 6.0 kb DNA fragment resulted in 1.97 kb. Similarly, an extra segment in pNHJ20L was cleaved off with EcoRI and SacI: The 9.4 kb DNA fragment resulted in 1.73 kb. These DNA fragments were sequenced by the Sanger method [Sanger, F., Science 214: 1205-1210 (1981)] using M13 phage vector. The nucleotide sequence of the 1.97 kb DNA fragment (pNHJ10H) and the 1.73 kb DNA fragment (pNHJ20L) are shown in the Sequence Listing by SEQ ID: No. 14 and SEQ ID: No. 15, respectively. The amino acid sequence deduced from the nucleotide sequence was found fully identical to the amino acid sequence as determined in (1). The sequence analysis also revealed that the DNA fragment contained the sequence coding for the α- and β-subunits. (8) Production of Nitrile Hydratase Using the Transformant and Conversion of Nitriles to Amides Using Nitrile Hydratase TG1 /pNHJ10H and TG1/pNHJ20L were inoculated into 10 ml of 2×YT medium containing 50 µg/ml of ampicillin and incubated at 30°C overnight (12 hours). 1 ml of the resultant culture was added to 100 ml of 2×YT medium (50 µg/ml of ampicillin, 0.1 g of CoCl₂·6H₂O/ℓ). The mixture was incubated at 30°C for 4 hours. IPTG was added to the mixture to a final concentration of 1 mM. The mixture was incubated at 30°C for 10 hours. After harvesting the cells, the cells were suspended in 5 ml of 0.1 M phosphate buffer (pH 7.5). The suspensions were disrupted by sonification for 5 min and centrifuged at 12,000 ×g for 30 min. The resulting supernatants were used for the enzyme assay. The enzyme assay was carried out in a reaction mixture (12 ml) containing 50 mM potassium phosphate buffer (pH 7.5), 6 mM benzonitrile and an appropriate amount of the enzyme. The reaction was carried out at 20°C for 30 min and stopped by the addition of 0.2 ml 1 M HCl. The amount of benzamide formed in the reaction mixture was determined by HPLC. As a control, the mixture obtained by the same procedure as described above but from E . coli TG1 was used. The levels of nitrile hydratase activity in cell-free extracts of E . coli containing pNHJ10H and pNHJ20L were 1.75 × 10⁻³ and 6.99 × 10⁻³ units/mg, respectively, when cultured in 2×YT medium in the presence of CoCl₂ and IPTG. Benzamide was found in the reaction mixture of TG1/pNHJ10H and pNHJ20L, whereas no benzamide was found in the reaction mixture of TG1 . (1) INFORMATION FOR SEQ ID NO: 1 (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 203 amino acids (B) TYPE: Amino acid (C) STRANDEDNESS: (D) TOPOLOGY: Linear (ii) MOLECULE TYPE: Peptide (vi) ORIGINAL SOURCE (A) ORGANISM: Rhodococcus rhodochrous (B) STRAIN: J-1 (FERM BP-1478) (ix) FEATURES (A) OTHER INFORMATION α (H) -subunit (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 1 (2) INFORMATION FOR SEQ ID NO: 2 (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 229 amino acids (B) TYPE: Amino acid (C) STRANDEDNESS: (D) TOPOLOGY: Linear (ii) MOLECULE TYPE: Peptide (vi) ORIGINAL SOURCE (A) ORGANISM: Rhodococcus rhodochrous (B) STRAIN: J-1 (FERM BP-1478) (ix) FEATURES (A) OTHER INFORMATION β (H) -subunit (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 2 (3) INFORMATION FOR SEQ ID NO: 3 (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 207 amino acids (B) TYPE: Amino acid (C) STRANDEDNESS: (D) TOPOLOGY: Linear (ii) MOLECULE TYPE: Peptide (vi) ORIGINAL SOURCE (A) ORGANISM: Rhodococcus rhodochrous (B) STRAIN: J-1 (FERM BP-1478) (ix) FEATURES (A) OTHER INFORMATION α (L) -subunit (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 3 (4) INFORMATION FOR SEQ ID NO: 4 (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 226 amino acids (B) TYPE: Amino acid (C) STRANDEDNESS: (D) TOPOLOGY: Linear (ii) MOLECULE TYPE: Peptide (vi) ORIGINAL SOURCE (A) ORGANISM: Rhodococcus rhodochrous (B) STRAIN: J-1 (FERM BP-1478) (ix) FEATURES (A) OTHER INFORMATION β (L) -subunit (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 4 (5) INFORMATION FOR SEQ ID NO: 5 (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 609 base pairs (B) TYPE: Nucleic acid (C) STRANDEDNESS: Single (D) TOPOLOGY: Linear (ii) MOLECULE TYPE: Genomic DNA (vi) ORIGINAL SOURCE (A) ORGANISM: Rhodococcus rhodochrous (B) STRAIN: J-1 (FERM BP-1478) (ix) FEATURES (A) OTHER INFORMATION α (H) -subunit (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 5 (6) INFORMATION FOR SEQ ID NO: 6 (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 687 nucleic acids (B) TYPE: Nucleic acid (C) STRANDEDNESS: Single (D) TOPOLOGY: Linear (ii) MOLECULE TYPE: Genomic DNA (vi) ORIGINAL SOURCE (A) ORGANISM: Rhodococcus rhodochrous (B) STRAIN: J-1 (FERM BP-1478) (ix) FEATURES (A) OTHER INFORMATION β (H) -subunit (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 6 (7) INFORMATION FOR SEQ ID NO: 7 (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 621 base pairs (B) TYPE: Nucleic acid (C) STRANDEDNESS: Single (D) TOPOLOGY: Linear (ii) MOLECULE TYPE: Genomic DNA (vi) ORIGINAL SOURCE (A) ORGANISM: Rhodococcus rhodochrous J-1 (FERM BP-1478) (ix) FEATURES (A) OTHER INFORMATION α (L) -subunit (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 7 (8) INFORMATION FOR SEQ ID NO: 8 (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 678 base pairs (B) TYPE: Nucleic acid (C) STRANDEDNESS: Single (D) TOPOLOGY: Linear (ii) MOLECULE TYPE: Genomic DNA (vi) ORIGINAL SOURCE (A) ORGANISM: Rhodococcus rhodochrous (B) STRAIN: J-1 (FERM BP-1478) (ix) FEATURES (A) OTHER INFORMATION β (L) -subunit (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 8 (9) INFORMATION FOR SEQ ID NO: 9 (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 26 amino acids (B) TYPE: Amino acid (C) STRANDEDNESS: (D) TOPOLOGY: Linear (ii) MOLECULE TYPE: Peptide (vi) ORIGINAL SOURCE (A) ORGANISM: Rhodococcus rhodochrous (B) STRAIN: J-1 (FERM BP-1478) (ix) FEATURES (A) OTHER INFORMATION α (H) -subunit: α 1 (H) (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 9 (10) INFORMATION FOR SEQ ID NO: 10 (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 28 amino acids (B) TYPE: Amino acid (C) STRANDEDNESS: (D) TOPOLOGY: Linear (ii) MOLECULE TYPE: Peptide (vi) ORIGINAL SOURCE (A) ORGANISM: Rhodococcus rhodochrous (B) STRAIN: J-1 (FERM BP-1478) (ix) FEATURES (A) OTHER INFORMATION β (H) -subunit: β 1 (H) (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 10 (11) INFORMATION FOR SEQ ID NO: 11 (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 15 amino acids (B) TYPE: Amino acid (C) STRANDEDNESS: (D) TOPOLOGY: Linear (ii) MOLECULE TYPE: Peptide (vi) ORIGINAL SOURCE (A) ORGANISM: Rhodococcus rhodochrous (B) STRAIN: J-1 (FERM BP-1478) (ix) FEATURES (A) OTHER INFORMATION α (L) -subunit: α 1 (L) (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 11 (12) INFORMATION FOR SEQ ID NO: 12 (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 19 amino acids (B) TYPE: Amino acid (C) STRANDEDNESS: (D) TOPOLOGY: Linear (ii) MOLECULE TYPE: Peptide (vi) ORIGINAL SOURCE (A) ORGANISM: Rhodococcus rhodochrous (B) STRAIN: J-1 (FERM BP-1478) (ix) FEATURES (A) OTHER INFORMATION β (L) -subunit: β 1 (L) (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 12 (13) INFORMATION FOR SEQ ID NO: 13 (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 2070 base pairs (B) TYPE: Nucleic acid (C) STRANDEDNESS: Single (D) TOPOLOGY: Linear (ii) MOLECULE TYPE: Genomic DNA (vi) ORIGINAL SOURCE (A) ORGANISM: Rhodococcus sp. (B) STRAIN: N-774 (FERM BP-1936) (ix) FEATURES from nucleotide No. 675 to 1295: subunit α from nucleotide No. 1225 to 1960: subunit β (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 13 (14) INFORMATION FOR SEQ ID NO: 14 (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 1970 base pairs (B) TYPE: Nucleic acid (C) STRANDEDNESS: Single (D) TOPOLOGY: Linear (ii) MOLECULE TYPE: Genomic DNA (vi) ORIGINAL SOURCE (A) ORGANISM: Rhodococcus rhodochrous J-1 (FERM BP-1478) (ix) FEATURES from nucleotide No. 408 to 1094: subunit β (H) from nucleotide No. 1111 to 1719: subunit α (H) (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 14 (15) INFORMATION FOR SEQ ID NO: 15 (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 1731 base pairs (B) TYPE: Nucleic acid (C) STRANDEDNESS: Single (D) TOPOLOGY: Linear (ii) MOLECULE TYPE: Genomic DNA (vi) ORIGINAL SOURCE (A) ORGANISM: Rhodococcus rhodochrous (B) STRAIN: J-1 (FERM BP-1478) (ix) FEATURES from nucleotide No. 171 to 848: subunit β (L) from nucleotide No. 915 to 1535: subunit α (L) (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 15

Claims: Claims for the following Contracting States : AT, BE, CH, DE, DK, FR, GB, IT, LI, NL, SE A DNA (H) fragment encoding a polypeptide having nitrile hydratase activity, said polypeptide comprising the α (H) -subunit as defined in the Sequence Listing by SEQ ID: No. 1 and the β (H) -subunit as defined in the Sequence Listing by SEQ ID: No. 2. A DNA (L) fragment encoding a polypeptide having nitrile hydratase activity, said polypeptide comprising the α (L) -subunit as defined in the Sequence Listing by SEQ ID: No. 3 and the β (L) -subunit as defined in the Sequence Listing by SEQ ID: No. 4. The DNA (H) fragment of claim 1 which contains the nucleotide sequences of the α (H) -subunit as defined in the Sequence Listing by SEQ ID: No. 5 and the β (H) -subunit as defined in the Sequence Listing by SEQ ID: No. 6. The DNA (L) fragment of claim 2 which contains the nucleotide sequences of the α (L) -subunit as defined in the Sequence Listing by SEQ ID: No. 7 and the β (L) -subunit as defined in the Sequence Listing by SEQ ID: No. 8. A recombinant DNA comprising a DNA (H) or DNA (L) of any one of claims 1-4 in a vector. A transformant transformed with the recombinant DNA of claim 5. A method of producing nitrile hydratase which comprises culturing the transformant as claimed in claim 6 and recovering nitrile hydratase from the culture. A method of producing amides which comprises hydrating nitriles using nitrile hydratase obtained from the culture of the transformant of claim 6. A method of producing amides which comprises culturing the transformant as claimed in claim 6, and hydrating nitriles to amides using the resultant culture, isolated bacterial cells, treated matter thereof, or a fixed material thereof. Claims for the following Contracting State : ES A method for the preparation of a DNA (H) fragment encoding a polypeptide having nitrile hydratase activity, said polypeptide comprising the α (H) -subunit as defined in the Sequence Listing by SEQ ID: No. 1 and the β (H) -subunit as defined in the Sequence Listing by SEQ ID: No. 2, which method comprises the screening of chromosomal DNA by Southern hybridization with a labelled probe which is capable of hybridizing with a nitrile hydratase gene, the isolation of a fragment hybridizing to said probe, the insertion of said fragment into a plasmid, amplification of said plasmid and isolation of the inserted fragment by excision with a restriction enzyme. A method for the preparation of a DNA (L) fragment encoding a polypeptide having nitrile hydratase activity, said polypeptide comprising the α (L) -subunit as defined in the Sequence Listing by SEQ ID: No. 3 and the β (L) -subunit as defined in the Sequence Listing by SEQ ID: No. 4, which method comprises the screening of chromosomal DNA by Southern hybridization with a labelled probe which is capable of hybridizing with a nitrile hydratase gene, the isolation of a fragment hybridizing to said probe, the insertion of said fragment into a plasmid, amplification of said plasmid and isolation of the inserted fragment by excision with a restriction enzyme. The method of claim 1 wherein the DNA (H) fragment contains the nucleotide sequences of the α (H) -subunit as defined in the Sequence Listing by SEQ ID: No. 5 and the β (H) -subunit as defined in the Sequence Listing by SEQ ID: No. 6. The method of claim 2 wherein the DNA (L) fragment contains the nucleotide sequences of the α (L) -subunit as defined in the Sequence Listing by SEQ ID: No. 7 and the β (L) -subunit as defined in the Sequence Listing by SEQ ID: No. 8. A method for the preparation of a recombinant DNA comprising a DNA (H) or DNA (L) fragment of any one of claims 1 to 4 comprising the insertion of said DNAs in a vector. A transformant transformed with the recombinant DNA prepared according to claim 5. A method of producing nitrile hydratase which comprises culturing the transformant as claimed in claim 6 and recovering nitrile hydratase from the culture. A method of producing amides which comprises hydrating nitriles using nitrile hydratase obtained from the culture of the transformant of claim 6. A method of producing amides which comprises culturing the transformant as claimed in claim 6, and hydrating nitriles to amides using the resultant culture, isolated bacterial cells, treated matter thereof, or a fixed material thereof.

Inventors: BEPPU TERUHIKO, HORINOUCHI SUEHARU, NAGASAWA TORU DR, NISHIYAMA MAKOTO DR, YAMADA HIDEAKI, HIDEAKI, YAMADA, MAKOTO, NISHIYAMA, SUEHARU HORINOUCHI, TERUHIKO, BEPPU, TORU, NAGASAWA
Applicants: BEPPU TERUHIKO, HIDEAKI YAMADA, NITTO CHEMICAL INDUSTRY CO LTD, BEPPU, TERUHIKO, NITTO CHEMICAL INDUSTRY CO., LTD., YAMADA, HIDEAKI
Application year: 1991
Main classification: C12N15
IPC codes: C12N9, C12R1, C12N1, C12N15, C12P13, C07H21