characterization of omethyltransferase scomt1 cloned from streptomyces coelicolor a32 the roles of omethyltransferases omts in microorganisms are not well understood and are suggested to increase antimicrobial activity studies on omts cloned from microorganisms may help elucidate their roles streptomyces coelicolor a32 produces many useful natural antibiotics such as actinorhodin based on sequence information from s coelicolor a32 genome it was possible to clone several methyltransferases an omt cloned from streptomyces coelicolor a32 scomt1 was characterized by in vivo and in vitro assays of 23 compounds tested 13 were found to serve as its substrates of the 13 substrates the methylated positions of 7 compounds were determined by hplc nmr and ms analyses this omt favored orthodihydroxyflavones among the compounds tested here the best substrate is 67dihydroxyflavone