[Identification and the physicochemical characteristics of the extrachromosomal DNA from a Streptomyces antibioticus strain].

The data on centrifugation of DNA in the density gradient of caesium chloride-ethidium bromide, electron microscopy and electrophoresis of the DNA restricts from the satellite gradient band indicate that Str. antibioticus, the oleandomycin-producing organism possessed extrachromosomal cyclic DNA with the molecular weight of 21.3. 10(6) +/- +/- 0.3 10(6) daltons. The extrachromosomal cyclic DNA had 7 identification sites for endonuclease BamHI, 5 sites for PstI, 12 sites for PvuII, more than 14 sites for SmaI and non for endonucleases Eco RI and HindIII.