2pnh

From Proteopedia

Revision as of 11:29, 21 November 2007

Escherichia coli PriB E39A variant

Overview

Collapsed DNA replication forks must be reactivated through, origin-independent reloading of the replication machinery (replisome) to, ensure complete duplication of cellular genomes. In E. coli, the, PriA-dependent pathway is the major replication restart mechanism and, requires primosome proteins PriA, PriB, and DnaT for replisome reloading., However, the molecular mechanisms that regulate origin-independent, replisome loading are not fully understood. Here, we demonstrate that, assembly of primosome protein complexes represents a key regulatory, mechanism, as inherently weak PriA-PriB and PriB-DnaT interactions are, strongly stimulated by single-stranded DNA. Furthermore, the binding site, on PriB for single-stranded DNA partially overlaps the binding sites for, PriA and DnaT, suggesting a dynamic primosome assembly process in which, single-stranded DNA is handed off from one primosome protein to another as, a repaired replication fork is reactivated. This model helps explain how, origin-independent initiation of DNA replication is restricted to repaired, replication forks, preventing overreplication of the genome.

About this Structure

2PNH is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.

Reference

A hand-off mechanism for primosome assembly in replication restart., Lopper M, Boonsombat R, Sandler SJ, Keck JL, Mol Cell. 2007 Jun 22;26(6):781-93. PMID:17588514

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