title: Restriction and modification in B. subtilis. The biochemical basis of modification against endo R. Bsu R restriction.
abstract: The content of 5-methylcytosine (5MC) and 6-methyladenine (6MA) in modified and nonmodified DNAs from B. subtilis and B. subtilis phage SPP1 were determined. Non-modified SPP1-O DNA contains about 15 5MC residues/molecule. Each modified SPP1-R DNA molecule carries 190 modification specific methyl groups. This number is sufficient to account for modification of the 80 restriction sites in SPP1 DNA (Bron and Murray, 1975) against endo R-Bsu R, assuming each modified site contains two 5MC residues. Resistance of SPO1 DNA against endo R-Bsu R restriction both in vivo and in vitro is probably not due to methylation of endo R-Bsu R recognition sites.
mesh_terms: D001412:Bacillus subtilis / Q000378:metabolism*; D001435:Bacteriophages / Q000378:metabolism*; D001483:Base Sequence; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000378:metabolism; D004269:DNA, Bacterial / Q000378:metabolism*; D004279:DNA, Viral / Q000378:metabolism*; D005796:Genes; D008745:Methylation
chemical_list: D004269:DNA, Bacterial; D004279:DNA, Viral; D004248:DNA (Cytosine-5-)-Methyltransferases