SEQUENCING OF COMAMONAS-TESTOSTERONI STRAIN B-356-BIPHENYL CHLOROBIPHENYL DIOXYGENASE GENES - EVOLUTIONARY RELATIONSHIPS AMONG GRAM-NEGATIVE BACTERIAL BIPHENYL DIOXYGENASES/

In a previous work, all three components of Comamonas testosteroni B-3 56 biphenyl (BPH)/chlorobiphenyls (PCBs) dioxygenase (dox) have been p urified and characterized. They include an iron-sulphur protein (ISPBP H) which is the terminal oxygenase composed of two subunits (encoded b y bphA and bphE), a ferredoxin (FER(BPH)) encoded by bphF and a reduct ase (RED(BPH)) encoded by bphG. bphG Is not located in the neighbourho od of bphAEF in B-356. We are reporting the cloning of B-356-bphG and the sequencing of B-356-BPH dox genes. Comparative analysis of the gen es provided genetic evidence showing that two BPH dox lineages have em erged in Gram-negative bacteria. The main features of the lineage that includes B-356 are the location of bphG outside the bph gene cluster and the structure of RED(BPH) which is very distinct from all other ar yl dioxygenase-reductases.