cis-2,3-dihydro-2,3-dihydroxybiphenyl dehydrogenase and cis-1,2-dihydro-1,2-dihydroxynaphathalene dehydrogenase catalyze dehydrogenation of the same range of substrates

Pseudomonas putida strain G7 cis-1,2-dihydro-1,2-dihydroxynaphthalene dehyd rogenase (NahB) and Comamonas testosteroni strain B-356 cis-2,3-dihydro-2,3 -dihydroxybiphenyl dehydrogenase (BphB) were found to be catalytically acti ve towards cis-2,3-dihydro-2,3-dihydroxybiphenyl (specificity factors of 50 1 and 5850 s(-1) mM(-1) respectively), cis-1,2-dihydro-1,2-dihydroxynaphtha lene (specificity factors of 204 and 193 s(-1) mM(-1) respectively) and 3,4 -dihydro-3,4-dihydroxy-2,2',5,5'-tetrachlorobiphenyl (specificity factors o f 1.6 and 4.9 s(-1) mM(-1) respectively). A key finding in this work is the capacity of strain B-356 BphB as well as Burkholderia cepacia strain LB400 BphB to catalyze dehydrogenation of 3,4-dihydro-3,4-dihydroxy-2,2',5,5'-te trachlorobiphenyl which is the metabolite resulting from the catalytic meta -para hydroxylation of 2,2',5,5'-tetrachlorobiphenyl by LB400 biphenyl diox ygenase. (C) 1999 Academic Press.