Inactivation of Individual SeqA Binding Sites of the E. coli Origin Reveals Robustness of Replication Initiation Synchrony.

ABSTRACT: The Escherichia coli origin of replication, oriC, comprises mostly binding sites of two proteins: DnaA, a positive regulator, and SeqA, a negative regulator. SeqA, although not essential, is required for timely initiation, and during rapid growth, synchronous initiation from multiple origins. Unlike DnaA, details of SeqA binding to oriC are limited. Here we have determined that SeqA binds to all its sites tested (9/11) and with variable efficiency. Titration of DnaA alters SeqA binding to two sites, both of which have overlapping DnaA sites. The altered SeqA binding, however, does not affect initiation synchrony. Synchrony is also unaffected when individual SeqA sites are mutated. An apparent exception was one mutant where the mutation also changed an overlapping DnaA site. In this mutant,

SUBMITTER: Jha JK 

PROVIDER: S-EPMC5145175 | biostudies-literature | 2016

REPOSITORIES: biostudies-literature