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.
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.
Shakibai
N
N
Department of Microbiology, University of Connecticut Health Center, Farmington, CT 06032, USA.
Ishidate
K
K
Reshetnyak
E
E
Gunji
S
S
Kohiyama
M
M
Rothfield
L
L
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
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