title: The ArcA/ArcB two-component regulatory system of Escherichia coli is essential for Xer site-specific recombination at psi.
abstract: Two recombinases, XerC and XerD, act at the recombination sites psi and cer in plasmids pSC101 and Co1E1 respectively. Recombination at these sites maintains the plasmids in a monomeric state and helps to promote stable plasmid inheritance. The accessory protein PepA acts at both psi and cer to ensure that only intramolecular recombination takes place. An additional accessory protein, ArgR, is required for recombination at cer but not at psi. Here, we demonstrate that the ArcA/ArcB two-component regulatory system of Escherichia coli, which mediates adaptation to anaerobic growth conditions, is required for efficient recombination in vivo at psi. Phosphorylated ArcA binds to psi in vitro and increases the efficiency of recombination at this site. Binding of ArcA to psi may contribute to the formation of a higher order synaptic complex between a pair of psi sites, thus helping to ensure that recombination is intramolecular.
authors.affiliation: Department of Biochemistry, University of Oxford, UK. sean@bioch.ox.ac.uk
authors.forename: S D
authors.initials: SD
authors.lastname: Colloms
authors.forename: C
authors.initials: C
authors.lastname: Alén
authors.forename: D J
authors.initials: DJ
authors.lastname: Sherratt
mesh_terms: D000693:Anaerobiosis; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites; D004254:DNA Nucleotidyltransferases / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D019426:Integrases; D008565:Membrane Proteins / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation; D010766:Phosphorylation; D010957:Plasmids / Q000235:genetics*; D011494:Protein Kinases; D045522:Recombinases; D011995:Recombination, Genetic; D012097:Repressor Proteins; D015398:Signal Transduction
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D045522:Recombinases; D012097:Repressor Proteins; C473360:XerC protein, E coli; C041610:arcA protein, E coli; D011494:Protein Kinases; C065271:arcB protein, E coli; D004254:DNA Nucleotidyltransferases; D019426:Integrases; C473361:XerD protein, E coli; C115006:integron integrase IntI1