title: DNA synthesis in Escherichia coli cells infected with gene H mutants of bacteriophage phi X174.
abstract: Escherichia coli cells infected with gene H mutants of bacteriophage phi X174 produce two types of particles. The 110S particles contain single-stranded circular DNA; the 110S particles are not infectious, although their DNA is infectious for E. coli spheroplasts. The second type of particles, 70S particles, contain a fragment of single-stranded DNA ranging from 0.2 to 0.5 genome in length. This fragment DNA anneals only to restriction enzyme fragments of replicative-form DNA from the portion of the molecule corresponding to the origin and early region of phi X174 single-stranded synthesis, although full-round single-stranded DNA synthesis is occurring in the H mutant-infected cells. Different H mutant phages produce different proportions of 70S to 110S particles; those mutants producing the most 70S also exhibit the largest amount of degradation of intracellularly labeled DNA during infection. These results suggest that in H mutant-infected cells, full-length single-stranded DNA is synthesized; varying amounts of degradation of the single-stranded material occur, and the resulting fragment DNA is subsequently incorporated into 70S particles.
mesh_terms: D000327:Adsorption; D003090:Coliphages / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D004279:DNA, Viral / Q000096:biosynthesis*; D004926:Escherichia coli / Q000378:metabolism*; D005814:Genes, Viral; D009154:Mutation; D014764:Viral Proteins / Q000235:genetics
chemical_list: D004279:DNA, Viral; D014764:Viral Proteins