CLONING AND SEQUENCES OF THE FIRST 8 GENES OF THE CHROMOSOMALLY ENCODED (METHYL) PHENOL DEGRADATION PATHWAY FROM PSEUDOMONAS-PUTIDA-P35X

Pseudomonas putida P35X (NCIB 9869) metabolises phenol and cresols via a chromosomally encoded meta-cleavage pathway. A 13.4-kb fragment of the chromosome involved in encoding phenol catabolism was cloned and c haracterized. Deletion analysis and nucleotide sequencing of a 6589-bp region, in conjunction with enzyme assays, were used to identify the phhKLMNOP genes encoding the phenol hydroxylase, the phhB gene encodin g catechol 2,3-dioxygenase (EC 1.13.11.2) and the phhQ gene that encod es a small ferredoxin-like protein. The genes are organised in an oper on-like structure, in the order phhKLMNOPQB, and the deduced amino-aci d sequences share high homology (68.3-99.7%) with those of the plasmid -encoded genes dmpKLMNOPQB of Pseudomonas sp. strain CF600. Genetic ev idence is presented that the difference in the growth substrate ranges of Pseudomonas P35X and CF600 are due to the effector activation spec ificities of the regulators of these systems, rather than the substrat e specificities of the catabolic enzymes.