Identification and characterization of the dif Site from Bacillus subtilis.
Bacteria with circular chromosomes have evolved systems that ensure multimeric chromosomes, formed by homologous recombination between sister chromosomes during DNA replication, are resolved to monomers prior to cell division. The chromosome dimer resolution process in Escherichia coli is mediated by two tyrosine family site-specific recombinases, XerC and XerD, and requires septal localization of the division protein FtsK. The Xer recombinases act near the terminus of chromosome replication at a site known as dif (Ecdif). In Bacillus subtilis the RipX and CodV site-specific recombinases have been implicated in an analogous reaction. We present here genetic and biochemical evidence that a 28-bp sequence of DNA (Bsdif), lying 6 degrees counterclockwise from the B. subtilis terminus of replication (172 degrees ), is the site at which RipX and CodV catalyze site-specific recombination reactions required for normal chromosome partitioning. Bsdif in vivo recombination did not require the B. subtilis FtsK homologues, SpoIIIE and YtpT. We also show that the presence or absence of the B. subtilis SPbeta-bacteriophage, and in particular its yopP gene product, appears to strongly modulate the extent of the partitioning defects seen in codV strains and, to a lesser extent, those seen in ripX and dif strains.
Sciochetti
S A
SA
Department of Microbiology and Immunology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA.
Piggot
P J
PJ
Blakely
G W
GW
D001412:Bacillus subtilis / Q000235:genetics* / Q000648:ultrastructure; D001426:Bacterial Proteins / Q000378:metabolism; D002876:Chromosomes, Bacterial / Q000235:genetics* / Q000648:ultrastructure; D004254:DNA Nucleotidyltransferases / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism; D019281:Dimerization; D029968:Escherichia coli Proteins; D019426:Integrases; D008957:Models, Genetic; D010957:Plasmids / Q000235:genetics; D011485:Protein Binding; D011938:Rec A Recombinases / Q000235:genetics; D045522:Recombinases; D011995:Recombination, Genetic; D012808:Sigma Factor; D013171:Spores, Bacterial; D035181:TATA-Box Binding Protein; D014157:Transcription Factors / Q000378:metabolism
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D045522:Recombinases; D012808:Sigma Factor; D035181:TATA-Box Binding Protein; D014157:Transcription Factors; C473360:XerC protein, E coli; C121793:codV protein, Bacillus subtilis; C092468:spoIIR protein, Bacillus subtilis; C030069:spore-specific proteins, Bacillus; D004254:DNA Nucleotidyltransferases; D019426:Integrases; D011938:Rec A Recombinases; C473361:XerD protein, E coli; C115006:integron integrase IntI1