title: Studies on the biological role of DNA methylation: III Role in excision of one-genome long single-stranded phi X 174 DNA.
abstract: Accumulation of replicative intermediates of the bacteriophage phi X174 was observed in E. coli C infected cells when phage DNA methylation has been inhibited by nicotinamide or when cells were infected with a temperature-sensitive mutant in gene A. Analysis of the accumulating replicative intermediates by electron microscopy revealed that these molecules are composed of double-stranded DNA rings with multiple-genome length single-stranded "tails". These results suggest that the single 5-methylcytosine residue present in the phage DNA serves as a recognition site for the gene A protein mediating the excision of one-genome long phage DNA. This excision process is oligatory for the final maturation of the phage.
mesh_terms: D003090:Coliphages / Q000187:drug effects / Q000378:metabolism*; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000378:metabolism*; D004261:DNA Replication; D004277:DNA, Single-Stranded / Q000096:biosynthesis*; D004279:DNA, Viral / Q000096:biosynthesis*; D004926:Escherichia coli / Q000187:drug effects / Q000378:metabolism; D005814:Genes, Viral; D008780:Methyltransferases / Q000378:metabolism*; D008854:Microscopy, Electron; D009536:Niacinamide / Q000494:pharmacology; D014779:Virus Replication
chemical_list: D004277:DNA, Single-Stranded; D004279:DNA, Viral; D009536:Niacinamide; D008780:Methyltransferases; D004248:DNA (Cytosine-5-)-Methyltransferases