The phiX174-type primosome promotes replisome assembly at the site of recombination in bacteriophage Mu transposition.
Initiation of Escherichia coli DNA synthesis primed by homologous recombination is believed to require the phiX174-type primosome, a mobile priming apparatus assembled without the initiator protein DnaA. We show that this primosome plays an essential role in bacteriophage Mu DNA replication by transposition. Upon promoting transfer of Mu ends to target DNA, the Mu transpososome undergoes transition to a pre-replisome that permits initiation of DNA synthesis only in the presence of primosome assembly proteins PriA, DnaT, DnaB and DnaC. These assembly proteins promote the engagement of primase and DNA polymerase III holoenzyme, initiating semi-discontinuous replication preferentially at the Mu left end. The results indicate that these proteins play a crucial role in promoting replisome assembly on a recombination intermediate.
Jones
J M
JM
Department of Biochemistry and Molecular Biology, Georgetown University Medical Center, 3900 Reservoir Rd NW, Washington, DC 20007, USA.
Nakai
H
H
D001426:Bacterial Proteins / Q000378:metabolism*; D010583:Bacteriophage mu / Q000235:genetics*; D010584:Bacteriophage phi X 174; D004256:DNA Polymerase I / Q000378:metabolism; D004258:DNA Polymerase III / Q000378:metabolism; D004261:DNA Replication; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004926:Escherichia coli / Q000821:virology; D029968:Escherichia coli Proteins; D008957:Models, Genetic; D011995:Recombination, Genetic; D051716:Replication Protein A
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C104198:DnaT protein, E coli; D029968:Escherichia coli Proteins; C086004:PriB protein, E coli; D051716:Replication Protein A; D004256:DNA Polymerase I; D004258:DNA Polymerase III