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.

[1]  R. Herrmann,et al.  Transmembrane topology of the Rieske Fe/S protein of the cytochrome b6/f complex from spinach chloroplasts , 1997, FEBS letters.

[2]  T. Stokke,et al.  Coordinating DNA replication initiation with cell growth: differential roles for DnaA and SeqA proteins. , 1996, Proceedings of the National Academy of Sciences of the United States of America.

[3]  E. Crooke.  Regulation of chromosomal replication in E. coli: Sequestration and beyond , 1995, Cell.

[4]  K. Skarstad,et al.  E. coli SeqA protein binds oriC in two different methyl-modulated reactions appropriate to its roles in DNA replication initiation and origin sequestration , 1995, Cell.

[5]  A. Abeles,et al.  A protein that binds to the P1 origin core and the oriC 13mer region in a methylation‐specific fashion is the product of the host seqA gene. , 1995, The EMBO journal.

[6]  O. Fayet,et al.  Parental strand recognition of the DNA replication origin by the outer membrane in Escherichia coli. , 1994, The EMBO journal.

[7]  S. Buratowski,et al.  The basics of basal transcription by RNA polymerase II , 1994, Cell.

[8]  F. Hansen,et al.  The initiation cascade for chromosome replication in wild‐type and Dam methyltransferase deficient Escherichia coli cells. , 1994, The EMBO journal.

[9]  K. Skarstad,et al.  The initiator protein DnaA: evolution, properties and function. , 1994, Biochimica et biophysica acta.

[10]  L. Rothfield,et al.  Characterization of the Escherichia coli membrane domain responsible for binding oriC DNA , 1992, Journal of bacteriology.

[11]  A. Landoulsi,et al.  The E. coli cell surface specifically prevents the initiation of DNA replication at oriC on heminethylated DNA templates , 1990, Cell.

[12]  N. Kleckner,et al.  E. coli oriC and the dnaA gene promoter are sequestered from dam methyltransferase following the passage of the chromosomal replication fork , 1990, Cell.

[13]  P. D. de Boer,et al.  Central role for the Escherichia coli minC gene product in two different cell division-inhibition systems. , 1990, Proceedings of the National Academy of Sciences of the United States of America.

[14]  Moselio Schaechter,et al.  The replicative origin of the E. coli chromosome binds to cell membranes only when hemimethylated , 1988, Cell.

[15]  D. Russell,et al.  Hemimethylation prevents DNA replication in E. coli , 1987, Cell.