Catalytic activity of Pseudomonas putida strain G7 naphthalene 1,2-dioxygenase on biphenyl

Naphthalene dioxygenase (NAP dox) catalyzes the first reaction of the naphthalene catabolic pathway encoded by the NAH plasmid. Similar to other aryl hydroxylating dioxygenases, NAP dox introduces molecular oxygen on two vicinal carbons of the aromatic ring. In this work it is shown that Pseudomonas putida G7 NAP dox (NAP doxG7) can catalyze the oxygenation of biphenyl quite efficiently. Similar to biphenyl dioxygenase which is the homologous reaction of the biphenyl catabolic pathway, the enzyme attack biphenyl molecule onto the ortho-meta carbons preferentially. However, unlike biphenyl dioxygenase of Pseudomonas sp. LB400, NAP doxG7 dioxygenates a non negligible portion of the substrate onto the meta-para carbons.