Conserved and hybrid meta-cleavage operons from PAH-degrading BurkholderiaRP007

We have compared the sequence and gene order of meta-cleavage pathway opero ns from alpha- and gamma-subgroups of the Proteobacteria with operons from Burkholderia sp. strain RP007 which belongs to the beta-subgroup of the Pro teobacteria. Burkholderia RP007 was isolated for its ability to degrade phe nanthrene and contains two meta-cleavage operons. One exhibits a comparable gene order to previously characterised gamma-subgroup Proteobacterial (Pse udomonas) meta operons, whilst the other has distinctive features present i n both alpha- and gamma-subgroup Proteobacterial (Sphingomonas and Pseudomo nas) meta operons. Gene sequence conservation, highlighted by examining the phylogeny of Proteobacterial catechol 2,3-dioxygenase sequences, reveals t hat sequences generally cluster in a manner which correlates with the taxon omic grouping of the Proteobacterial subgroup from which they originated. ( C) 1999 Academic Press.