title: The deoxyribonucleic acid modification enzyme of bacteriophage P1.
abstract: The bacteriophage P1 modification enzyme, assayed by the specific methylation of unmodified bacteriophage 82 DNA, has been purified 500-fold from a bacteriophage P1 lysogen of Escherichia coli. The enzyme catalyses the incorporation of approximately 20-24 methyl groups per bacteriophage 82 DNA molecule. The sole product of methylation is 6-methylaminopurine. Methylation of unmodified bacteriophage DNA confers protection against a challenge by purified bacteriophage P1 restriction enzyme. The pH optimum is 6.0-6.25: the apparent K(m) for S-adenosyl-l-methionine is 5x10(-6)m.
mesh_terms: D000645:Ammonium Sulfate; D002374:Catalase; D002501:Centrifugation, Zonal; D002848:Chromatography, DEAE-Cellulose; D003090:Coliphages / Q000201:enzymology*; D004279:DNA, Viral; D003956:Dialysis; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008745:Methylation; D008780:Methyltransferases / Q000302:isolation & purification*; D009025:Morpholines; D011687:Purines; D012436:S-Adenosylmethionine; D013451:Sulfonic Acids; D014316:Tritium
chemical_list: D004279:DNA, Viral; D009025:Morpholines; D011687:Purines; D013451:Sulfonic Acids; D014316:Tritium; D012436:S-Adenosylmethionine; D002374:Catalase; D008780:Methyltransferases; D000645:Ammonium Sulfate