title: Enzymatic replication of viral and complementary strands of duplex DNA of phage phiX174 proceeds by seprate mechanisms.
abstract: Multiplication of the duplex, circular, phage phiX174DNA (replicative form, RF) in stage II of the replicative life cycle has been observed with a crude enzyme preparation [Eisenberg et al. (1976) Proc, Natl. Acad, Sci. USA 73, 1594-1597]. This stage has now been partially reconstituted with purified proteins and subdivided into two stages: II(+) and II(-). In stage II(+), viral (+) strand synthesis is carried out by four proteins: the phage-induced, cistron A-dependent protein, rep-dependent protein, DNA unwinding protein, and DNA polymerase III holenzyme. In stage II(-), complementary (-) strand synthesis utilizes the product of stage II(+) as template and the multiprotein system previously identified in the stage I synthesis of a complementary strand on the viral DNA template to produce RF. The multiprotein system includes DNA unwinding protein, proteins i and n, dnaB protein, dnaC protein, dnaG protein, and DNA polymerase III holoenzyme. A discussion of these two separate mechanism for synthesis of (+) and (-) strands suggests that they may account for essentially all the replicative stages in the life cycle of phiX174.
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism; D003090:Coliphages / Q000378:metabolism*; D004261:DNA Replication; D004270:DNA, Circular / Q000096:biosynthesis*; D004277:DNA, Single-Stranded / Q000378:metabolism; D004279:DNA, Viral / Q000032:analysis / Q000096:biosynthesis*; D008954:Models, Biological; D013698:Templates, Genetic; D014764:Viral Proteins / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D004270:DNA, Circular; D004277:DNA, Single-Stranded; D004279:DNA, Viral; D014764:Viral Proteins