Determination of methylenomycin A synthesis by the pSV1 plasmid from Streptomyces violaceus-ruber SANK 95570.

A plasmid (pSV1) of 110 x 10(6) daltons from a methylenomycin A producing strain of Streptomyces violaceus-ruber was detected on an isolated from agarose gels. Elimination of this plasmid by protoplasting and regeneration resulted in the simultaneous loss of methylenomycin A production and resistance. pSV1 hybridized with pBR322 containing a cloned fragment of 1.7 x 10(6) daltons from S. coelicolor A3(2) which codes for methylenomycin A resistance. The pSV1 plasmid could be transferred to S. lividans by conjugation and by transformation and plasmid DNA identical in size to pSV1 could be isolated from the recipient strains. These experiments show that pSV1 codes for methylenomycin A production and resistance, in close analogy to the SCP1 plasmid from S. coelicolor A3(2).