Wang Yulong, Niemi Jarmo, Mäntsälä Pekka
Department of Biochemistry and Food Chemistry, University of Turku, FIN-20014, Turku, Finland.
FEMS Microbiol Lett. 2002 Feb 19;208(1):117-22. doi: 10.1111/j.1574-6968.2002.tb11070.x.
The rdm genes B, C and E from Streptomyces purpurascens encode enzymes that tailor aklavinone and aclacinomycins. We report that in addition to hydroxylation of aklavinone to epsilon-rhodomycinone, RdmE (aklavinone-11-hydroxylase) hydroxylated 11-deoxy-beta-rhodomycinone to beta-rhodomycinone both in vivo and in vitro. 15-Demethoxyaklavinone and decarbomethoxyaklavinone did not serve as substrates. RdmC (aclacinomycin methyl esterase) converted aclacinomycin T (AcmT) to 15-demethoxyaclacinomycin T, which was in turn converted to 10-decarbomethoxyaclacinomycin T and then to rhodomycin B by RdmB (aclacinomycin-10-hydroxylase). RdmC and RdmB were most active on AcmT, the one-sugar derivative, with their activity decreasing by 70-90% on two- and three-sugar aclacinomycins. Aclacinomycin A competitively inhibited the AcmT modifications at C-10. The results presented here suggest that in vivo the modifications at C-10 take place principally after addition of the first sugar.
来自紫色链霉菌的rdm基因B、C和E编码修饰阿克拉酮和阿克拉霉素的酶。我们报道，除了将阿克拉酮羟基化为ε-红霉酮外，RdmE（阿克拉酮-11-羟化酶）在体内和体外均能将11-脱氧-β-红霉酮羟基化为β-红霉酮。15-去甲氧基阿克拉酮和去甲羧基阿克拉酮不作为底物。RdmC（阿克拉霉素甲酯酶）将阿克拉霉素T（AcmT）转化为15-去甲氧基阿克拉霉素T，后者又被RdmB（阿克拉霉素-10-羟化酶）转化为10-去甲羧基阿克拉霉素T，然后再转化为红霉霉素B。RdmC和RdmB对单糖衍生物AcmT的活性最高，对二糖和三糖阿克拉霉素的活性降低70-90%。阿克拉霉素A竞争性抑制C-10位的AcmT修饰。此处给出的结果表明，在体内，C-10位的修饰主要在第一个糖添加后发生。
