NUCLEOTIDE-SEQUENCE OF A GENE ENCODING AN ORGANOPHOSPHORUS NERVE AGENT DEGRADING ENZYME FROM ALTEROMONAS-HALOPLANKTIS

Organophosphorus acid anhydrolases (OPAA) catalyzing the hydrolysis of a variety of toxic organophosphorus cholinesterase inhibitors offer p otential for decontamination of G-type nerve agents and pesticides, Th e gene (opa) encoding an OPAA was cloned from the chromosomal DNA of A lteromonas haloplanktis ATCC 23821, The nucleotide sequence of the 1,7 -kb DNA fragment contained the opa gene (1.3 kb) and its flanking regi on. We report structural and functional similarity of OPAAs from A. ha loplanktis and Alteromonas sp JD6.5 with the enzyme prolidase that hyd rolyzes dipeptides with a prolyl residue in the carboxyl-terminal posi tion. These results corroborate the earlier conclusion that the OPAA i s a type of X-Pro dipeptidase, and that X-Pro could be the native subs trate for such an enzyme in Alteromonas cells.