Independent Control of Replication Initiation of the Two Vibrio cholerae Chromosomes by DnaA and RctB

Abstract
Although the two Vibrio cholerae chromosomes initiate replication in a coordinated fashion, we show here that each chromosome appears to have a specific replication initiator. DnaA overproduction promoted overinitiation of chromosome I and not chromosome II. In contrast, overproduction of RctB, a protein that binds to the origin of replication of chromosome II, promoted overinitiation of chromosome II and not chromosome I.