title: The deoxyribonucleic acid-modification enzyme of bacteriophage P1. Subunit structure.
abstract: The bacteriophage P1 modification enzyme was purified 1400-fold from induced lysogens of a thermoinducible mutant of bacteriophage P1. The most purified fraction, when analysed by polyacrylamide-gel electrophoresis in sodium dodecyl sulphate, showed two principal stained bands. The two bands co-sedimented in a glycerol gradient with the modification activity, at a rate which, when compared with the rate of sedimentation of marker proteins, corresponds to a sedimentation coefficient in water of 6S. The mobilities of the bands on sodium dodecyl sulphate-polyacrylamide-gel electrophoresis corresponded to polypeptides of molecular weight 70000 and 45000 and they were present in equimolar amounts. It was concluded that the 6S species of the enzyme is a dimer of unlike subunits.
mesh_terms: D000645:Ammonium Sulfate; D002499:Centrifugation, Density Gradient; D003090:Coliphages / Q000201:enzymology*; D004279:DNA, Viral; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli; D008780:Methyltransferases / Q000302:isolation & purification*; D008970:Molecular Weight; D012436:S-Adenosylmethionine; D012967:Sodium Dodecyl Sulfate; D013347:Subcellular Fractions
chemical_list: D004279:DNA, Viral; D012967:Sodium Dodecyl Sulfate; D012436:S-Adenosylmethionine; D008780:Methyltransferases; D000645:Ammonium Sulfate