The DnaK Chaperone Uses Different Mechanisms To Promote and Inhibit Replication of Vibrio cholerae Chromosome 2.

ABSTRACT: Replication of Vibrio cholerae chromosome 2 (Chr2) depends on molecular chaperone DnaK to facilitate binding of the initiator (RctB) to the replication origin. The binding occurs at two kinds of site, 12-mers and 39-mers, which promote and inhibit replication, respectively. Here we show that DnaK employs different mechanisms to enhance the two kinds of binding. We found that mutations in rctB that reduce DnaK binding also reduce 12-mer binding and initiation. The initiation defect is suppressed by second-site mutations that increase 12-mer binding only marginally. Instead, they reduce replication inhibitory mechanisms: RctB dimerization and 39-mer binding. One suppressing change was in a dimerization domain which is folded similarly to the initiator of an iteron plasmid-the p

SUBMITTER: Jha JK 

PROVIDER: S-EPMC5395669 | biostudies-literature | 2017 Apr

REPOSITORIES: biostudies-literature