NahW, a novel, inducible salicylate hydroxylase involved in mineralizationof naphthalene by Pseudomonas stutzeri AN10

Two genes, nahG and nahW encoding two independent salicylate l-hydroxylases have been identified in the naphthalene-degrading strain Pseudomonas stutz eri AN10. While nahG resides in the same transcriptional unit as the meta-c leavage pathway genes, forming the naphthalene degradation lower pathway, n ahW is situated outside but in close proximity to this transcriptional unit . The nahG and nahW genes of P. stutzeri AN10 are induced and expressed upo n incubation,vith salicylate, and the enzymes that are encoded, NahG and Na hW, are involved in naphthalene and salicylate metabolism. Both genes, nahG and nahW have been cloned in Escherichia coli JM109. The overexpression of these genes yields peptides with apparent molecular masses of 46 kDa (NahG ) and 43 kDa (NahW), respectively. Both enzymes exhibit broad substrate spe cificities and metabolize salicylate, methylsalicylates, and chlorosalicyla tes. However, the relative rates by which the substituted analogs are trans formed differ considerably.