title: Replication cycle dependent association of SeqA to the outer membrane fraction of E. coli.
abstract: The hemimethylated oriC binding activity of the E. coli heavy density membrane fraction (outer membrane) was investigated by DNase I footprinting experiments using membranes obtained from different replication stages of PC-2 (dnaCts) cells. The maximal binding activity was found at the beginning of replication cycle and then decreased gradually. The same pattern of variation was observed with SeqA protein detected in the membranes by immunoblotting. Both binding activity and the presence of SeqA were conserved in the outer membrane even after floating centrifugation of the heavy density membrane fraction in a sucrose gradient, indicating that SeqA in fact can associate with the membrane and that this association varies according to replication cycle. Site specific binding to hemimethylated oriC, of the heavy density membrane obtained from seqA mutant, could be restored by addition of a low amount of His-tagged SeqA protein.
authors.affiliation: Equipe de Biochimie Génétique, Institut Jacques Monod, CNRS-Université Paris 6-7, 2, place Jussieu, 75251 Paris Cedex 05, France.
authors.forename: E
authors.initials: E
authors.lastname: d'Alençon
authors.forename: A
authors.initials: A
authors.lastname: Taghbalout
authors.forename: R
authors.initials: R
authors.lastname: Kern
authors.forename: M
authors.initials: M
authors.lastname: Kohiyama
mesh_terms: D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002453:Cell Cycle; D002458:Cell Fractionation; D002462:Cell Membrane / Q000378:metabolism; D019175:DNA Methylation; D004261:DNA Replication; D004269:DNA, Bacterial / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins; D004926:Escherichia coli / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins; D009154:Mutation; D018741:Replication Origin; D014157:Transcription Factors
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C089746:SeqA protein, E coli; D014157:Transcription Factors