title: Gene A product of phi X174 is required for site-specific endonucleolytic cleavage during single-stranded DNA synthesis in vivo.
abstract: A functional gene A product of phi X174 was found to be required at the stage of single-stranded DNA synthesis. A precursor complex that synthesizes single-stranded DNA (50S complex [Fujisawa and Hayashi, 1976]) was isolated from cells infected with wild-type or with temperature-sensitive gene A mutant phage. Proper cleavage of the single-stranded viral DNA did not occur in cells infected with the temperature-sensitive gene A mutant under restrictive conditions. This resulted in (i) accumulation of linear viral DNA molecules of 2 units in length in the 50S complex and (ii) cessation of elongation of viral-strand DNA after one complete cycle of single-stranded DNA synthesis.
mesh_terms: D003090:Coliphages / Q000201:enzymology / Q000378:metabolism*; D004261:DNA Replication; D004277:DNA, Single-Stranded / Q000096:biosynthesis*; D004279:DNA, Viral / Q000096:biosynthesis*; D004720:Endonucleases / Q000096:biosynthesis* / Q000378:metabolism; D005796:Genes; D009154:Mutation; D013696:Temperature
chemical_list: D004277:DNA, Single-Stranded; D004279:DNA, Viral; D004720:Endonucleases