Salicylate Hydroxylase, a Monooxygenase Requiring Flavin Adenine Dinucleotide. I. Purification and General Properties.

Hydroxylation reactions play important roles in many biosynthetic and catabolic processes. The mechanism of enzymatic hydroxylation reactions, however, has not been fully understood, mainly because the enzymes that catalyze such reactions are particulate or unstable and the extensive purification has met with great difficulties. In a preliminary report (2), we described the isolation from a soil bacterium of salicylate hydroxylase which catalyzes the stoichiometric formation of catechol from salicylate and reduced pyridine nucleotide in the presence of flavin adenine dinucleotide as a specific cofactor. This report deals with the purification of the enzyme and some of its properties. The accompanying paper (3) will describe the results of studies on the reaction mechanism, especially on the role of FAD and the results of experiments with ‘80.