Overexpression of the Replicative Helicase in Escherichia coli Inhibits Replication Initiation and Replication Fork Reloading.

ABSTRACT: Replicative helicases play central roles in chromosome duplication and their assembly onto DNA is regulated via initiators and helicase loader proteins. The Escherichia coli replicative helicase DnaB and the helicase loader DnaC form a DnaB6-DnaC6 complex that is required for loading DnaB onto single-stranded DNA. Overexpression of dnaC inhibits replication by promoting continual rebinding of DnaC to DnaB and consequent prevention of helicase translocation. Here we show that overexpression of dnaB also inhibits growth and chromosome duplication. This inhibition is countered by co-overexpression of wild-type DnaC but not of a DnaC mutant that cannot interact with DnaB, indicating that a reduction in DnaB6-DnaC6 concentration is responsible for the phenotypes associated with elevated DnaB co

SUBMITTER: Bruning JG 

PROVIDER: S-EPMC4828956 | biostudies-literature | 2016 Mar

REPOSITORIES: biostudies-literature