Isolated DNA encoding a nitrilase polypeptide, hosts containing, and expression thereof optionally assisted by a E. coli GroE chaperone polypeptide

An isolated and purified DNA segment coding for a polypeptide having nitrilase activity and that hydrolyzes nitriles to carboxylates, wherein said DNA segment is selected from the group consisting of:

• a DNA sequence coding for a polypeptide having nitrilase activity and nucleotide sequence SEQ ID NO:
• 4, as shown in FIG. 4A and 4B,
• a degenerate of said DNA sequence resulting from the degeneracy of the genetic code, and
• a DNA molecule that hybridizes with the complement of said DNA sequence under the following conditions:
• hybridization buffer:
• 5.times.SSC, 5.times.Denhardt, 0.1% SDS, 50 mM Na.sub.3 PO.sub.4, pH 6.5, 250 .mu.g/ml of ssDNA;
• hybridization temperature:
• 50.degree. C.;
• washing conditions:
• 1 h, 6.times.SSC, room temperature, and 5 min, 2.times.SSC, 0.1% SDS, 50.degree. C., and which isolated and purified DNA segment ranges in size from about 4.1 Kilobases to about 1064 bases and which codes for a polypeptide having nitrilase activity that hydrolyzes nitrites to carboxylates;
• and that hydrolyzes to a carboxylate, a dinitrile of the formula NC--R--CN in which R is an alkylene group having from 1 to 10 carbon atoms, or a mononitrile preferably belonging to the class of aliphatic sulphurized mononitriles.