Conserved and hybrid meta-cleavage operons from PAH-degrading Burkholderia RP007.

We have compared the sequence and gene order of meta-cleavage pathway operons from alpha- and gamma-subgroups of the Proteobacteria with operons from Burkholderia sp. strain RP007 which belongs to the beta-subgroup of the Proteobacteria. Burkholderia RP007 was isolated for its ability to degrade phenanthrene and contains two meta-cleavage operons. One exhibits a comparable gene order to previously characterised gamma-subgroup Proteobacterial (Pseudomonas) meta operons, whilst the other has distinctive features present in both alpha- and gamma-subgroup Proteobacterial (Sphingomonas and Pseudomonas) meta operons. Gene sequence conservation, highlighted by examining the phylogeny of Proteobacterial catechol 2,3-dioxygenase sequences, reveals that sequences generally cluster in a manner which correlates with the taxonomic grouping of the Proteobacterial subgroup from which they originated.