PriA and phage T4 gp59: factors that promote DNA replication on forked DNA substrates microreview.
The initiation of DNA synthesis on forked DNA templates is a vital process in the replication and maintenance of cellular chromosomes. Two proteins that promote replisome assembly on DNA forks have so far been identified. In phage T4 development the gene 59 protein (gp59) assembles replisomes at D-loops, the sites of homologous strand exchange. Bacterial PriA protein plays an analogous function, most probably restarting replication after replication fork arrest with the aid of homologous recombination proteins, and PriA is also required for phage Mu replication by transposition. Gp59 and PriA exhibit similar DNA fork binding activities, but PriA also has a 3' to 5' helicase activity that can promote duplex opening for replisome assembly. The helicase activity allows PriA's repertoire of templates to be more diverse than that of gp59. It may give PriA the versatility to restart DNA replication without recombination on arrested replication forks that lack appropriate duplex openings.
Jones
J M
JM
Department of Biochemistry and Molecular Biology, Georgetown University Medical Center, 331 Basic Science Building, 3900 Reservoir Road NW, Washington DC 20007, USA.
Nakai
H
H
D017122:Bacteriophage T4 / Q000235:genetics* / Q000378:metabolism*; D004265:DNA Helicases / Q000378:metabolism; D004261:DNA Replication; D004279:DNA, Viral / Q000737:chemistry / Q000235:genetics; D004268:DNA-Binding Proteins / Q000378:metabolism*; D009690:Nucleic Acid Conformation; D011995:Recombination, Genetic; D051716:Replication Protein A; D014764:Viral Proteins / Q000378:metabolism*
D004279:DNA, Viral; D004268:DNA-Binding Proteins; D051716:Replication Protein A; D014764:Viral Proteins; C091225:gene 59 protein, Enterobacteria phage T4; D004265:DNA Helicases