A LINEAR PLASMID-LIKE DNA IN STREPTOMYCES SP. PRODUCING LANKACIDIN GROUP ANTIBIOTICS

Abstract
A linear plasmid-like DNA was isolated by Agarose gel electrophoresis from a lysate of Streptomyces sp. 7434-AN4 which produces lankacidin group antibodics. The DNA (pSLA2) with MW of 11.2 .times. 106 was cleaved into 5 and 3 fragments, respectively, with XmaI and BamNI on the definite sites from the end, but not digested by EcoRI and HindIII. Upon treatment of the strain with ethidium bromide, variants were obtained which have lost the ability to produce the antibiotics. These variants lost pSLA2. The linear plasmid-like DNA is apparently involved in the production of lankacidin group antibiotics.