title: Replication of bacteriophage G13 DNA in dna mutants of Escherichia coli.
abstract: Host functions required for replication of microvirid phage G13 DNA were investigated in vivo, using thermosensitive dna mutants of Escherichia coli. In dna+ bacteria, conversion of viral single-stranded DNA into double-stranded replicative form (stage I synthesis) was resistant to 150 microgram/ml of chloramphenicol or 200 microgram/ml of rifampicin. Although multiplication of G13 phage was severely inhibited at 42--43 degrees C even in dna+ host, considerable amount of parental replicative form was synthesized at 43 degrees C in dna+, dnaA or dnaE bacteria. In dnaB and dnaG mutants, however, synthesis of parental replicative form was severely inhibited at the restrictive temperature. Interestingly enough, stage I replication of G13 DNA was, unlike that of phiX174, dependent on host dnaC(D) function. Moreover, the stage I synthesis of G13 DNA in dnaZ was thermosensitive in nutrient broth but not in Tris/casamino acids/glucose medium. In contrast with the stage I replication, synthesis of G13 progeny replicative form was remarkably thermosensitive even in dna+ or dnA cells.
mesh_terms: D003090:Coliphages / Q000235:genetics*; D004261:DNA Replication; D004277:DNA, Single-Stranded / Q000096:biosynthesis; D004279:DNA, Viral / Q000096:biosynthesis*; D004926:Escherichia coli / Q000235:genetics*; D009154:Mutation; D013696:Temperature; D014779:Virus Replication
chemical_list: D004277:DNA, Single-Stranded; D004279:DNA, Viral