title: Protein binding sites involved in the assembly of the KplE1 prophage intasome.
abstract: The organization of the recombination regions of the KplE1 prophage in Escherichia coli K12 differs from that observed in the lambda prophage. Indeed, the binding sites characterized for the IntS integrase, the TorI recombination directionality factor (RDF) and the integration host factor (IHF) vary in number, spacing and orientation on the attL and attR regions. In this paper, we performed site-directed mutagenesis of the recombination sites to decipher if all sites are essential for the site-specific recombination reaction and how the KplE1 intasome is assembled. We also show that TorI and IntS form oligomers that are stabilized in the presence of their target DNA. Moreover, we found that IHF is the only nucleoid associated protein (NAP) involved in KplE1 recombination, although it is dispensable. This is consistent with the presence of only one functional IHF site on attR and none on attL.
authors.affiliation: Laboratoire de Chimie Bactérienne CNRS UPR9043, Institut de Microbiologie de la Méditerranée, Marseille Cedex 20, France.
authors.forename: Gaël
authors.initials: G
authors.lastname: Panis
authors.forename: Yohann
authors.initials: Y
authors.lastname: Duverger
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Champ
authors.forename: Mireille
authors.initials: M
authors.lastname: Ansaldi
mesh_terms: D001287:Attachment Sites, Microbiological; D001483:Base Sequence; D001665:Binding Sites; D004279:DNA, Viral / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D048168:Escherichia coli K12 / Q000821:virology*; D029968:Escherichia coli Proteins / Q000378:metabolism; D019426:Integrases / Q000378:metabolism; D034982:Integration Host Factors / Q000378:metabolism; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D039002:Prophages / Q000235:genetics*; D011485:Protein Binding; D055503:Protein Multimerization; D016662:Virus Integration
chemical_list: D004279:DNA, Viral; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D034982:Integration Host Factors; C488589:TorI protein, E coli; D019426:Integrases