title: High-affinity binding of hemimethylated oriC by Escherichia coli membranes is mediated by a multiprotein system that includes SeqA and a newly identified factor, SeqB.
abstract: The binding of hemimethylated oriC to Escherichia coli membranes has been implicated in the prevention of premature reinitiation at newly replicated chromosomal origins in a reaction that involves the SeqA protein. We describe the resolution of the membrane-associated oriC-binding activity into two fractions, both of which are required for the high-affinity binding of hemimethylated oriC. The active component in one fraction is identified as SeqA. The active component of the second fraction is a previously undescribed protein factor, SeqB. The reconstituted system reproduced the salient characteristics of the membrane-associated binding activity, suggesting that the membrane-associated oriC-binding machinery of E. coli is likely to be a multiprotein system that includes the SeqA and SeqB proteins.
authors.affiliation: Department of Microbiology, University of Connecticut Health Center, Farmington, CT 06032, USA.
authors.forename: N
authors.initials: N
authors.lastname: Shakibai
authors.forename: K
authors.initials: K
authors.lastname: Ishidate
authors.forename: E
authors.initials: E
authors.lastname: Reshetnyak
authors.forename: S
authors.initials: S
authors.lastname: Gunji
authors.forename: M
authors.initials: M
authors.lastname: Kohiyama
authors.forename: L
authors.initials: L
authors.lastname: Rothfield
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004926:Escherichia coli / Q000502:physiology*; D029968:Escherichia coli Proteins; D015151:Immunoblotting; D008565:Membrane Proteins / Q000737:chemistry*; D011402:Pronase / Q000378:metabolism; D011485:Protein Binding / Q000502:physiology; D018741:Replication Origin / Q000235:genetics*; D012995:Solubility; D013861:Thiocyanates / Q000494:pharmacology; D014157:Transcription Factors
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; C089746:SeqA protein, E coli; D013861:Thiocyanates; D014157:Transcription Factors; D011402:Pronase; C009941:potassium thiocyanate