Isolation and characterization of plasmid from the Bacillus brevis var. G.-B. cells

The plasmid designated pAD1 was isolated from the cells of four variants of Bacillus brevis var. G.-B. The plasmid DNA has a molecular weight of about 47.1 x 10(6) daltons and contains 43.4 mole % G+C. The bulk of pAD1 DNA (96--98%) is associated with the fraction of chromosome DNA and membranes. Restriction endonucleases Sma I, Sal I and Bam HI cleaved the plasmid DNA into two, two and six fragments, respectively. The cleavage map of the pAD1 genome has been constructed for these three endonucleases. Restriction enzymes Eco RI, Hind III, Kpn I and Pst I hydrolized the plasmid DNA into 16, 21, 10 and 9 fragments, respectively. The presence of repeated sequences in the plasmid genome was shown based on pAD1 DNA cleavage by these endonucleases.