Structure of catechol 2,3-dioxygenase gene encoded in chromosomal DNA of Pseudomonas putida KF715

A catechol 2,3-dioxygenase gene in chromosomal DNA of P. putida KF715 was cloned and its nucleotide sequence analyzed. The enzyme gene was composed of 924 base pairs with ATG initiation codon and TGA termination codon, which can encode a polypeptide of molecular weight 35 kDa containing 307 amino acids. A promoter-like sequence and a ribosome-binding sequence were identified upstream the enzyme gene. A deduced amino acid sequence of the catechol 2,3-dioxygenase exhibited 94% identity with that of corresponding enzyme in TOL plasmid and 25% identity with that of 2,3-dihydroxybiphenyl 1,2-dioxygenase from the same strain. Furthermore, sequence comparison of the catechol 2,3-dioxygenase with other extradiol-type dioxygenases has led to identify evolutionally conserved amino acid residues whose possible catalytic roles are proposed.