1513-DMIA AND 1513-DMIB, DNA METHYLTRANSFERASE INHIBITORS PRODUCED BY STREPTOMYCES SP. STRAIN NO. 1513

AbstractTwo new methyltransferase inhibitors were isolated from the culture filtrate of Streptomyces sp. strain No. 1513 and named 1513-DMIa and 1513-DMIb. 1513-DMIa and 1513-DMIb were distinguished in certain properties from DMI-1, DMI-2, DMI-3 and DMI-4 previously reported. The molecular weight of 1513-DMIa and 1513-DMIb were estimated to be 576 and 8400 from the results of FAB-MS and gel filtration, respectively. The inhibitory activities of 1513-DMIa and 1513-DMIb were shown to be pH-and temperature-dependent and both inhibited M. EcoRI in an uncompetitive manner with respect to DNA or S-adenosylmethionine (SAM).