THE ENZYMATIC METHYLATION OF RNA AND DNA, VIII. EFFECTS OF BACTERIOPHAGE INFECTION ON THE ACTIVITY OF THE METHYLATING ENZYMES

Abstract

Infection of Escherichia coli-B with bacteriophage-T2 leads to a more than 100-fold increase in the rate of methylation of DNA by cell-free extracts. Smaller increases are seen after infection with phages-T1 and-T4. No changes in the methylation of soluble RNA and ribosomal RNA are observed. Infection with phage-T3 results in the appearance of an enzyme which cleaves S -adenosylmethionine, the methyl group donor in nucleic-acid methylation. The products of this cleavage appear to be thiomethyladenosine and homoserine which occur in equivalent amounts.