Control of chromosome replication in bacteria

The bacterial cell contain one chromosome, which carries the genetic information for the enzymes and structural proteins, which are essential for metabolism, growth, and cell division. The basis for the multiplication of living cells is the precise duplication of the genetic material - the chromosome(s) - by DNA replication, and the precise distribution of the duplicated chromosome(s) to two daughter cells. The basic aim in this project is to characterize the molecular clock, which governs initiation of chromosome replication, a process which takes place once and only once during the life cycle of any living organism. During recent years we have been involved in describing many of the wheels and balances of this molecular clock: The replication startpoint, the origin of replication, has been isolated and characterized; the gene for the central initiator protein has been isolated and characterized; and we have been involved in the characterization of several other factors which influences initiation of chromosome replication.
Subprojects being pursued during 1998:
1) Function of the DnaA protein in the autogenous regulation of the dnaA gene
2) The role of the DnaA protein and DnaA protein binding sites - DnaA boxes - in control of initiation
3) Characterization of DnaA suppressors in RNA polymerase
4) The role of Dam methylation in control of initiation of chromosome replication
5) The DNA replication rate of the bacterial chromosome studied as a function of the chromosome initiation frequency
6) Computer simulations of the Initiator Titration Model, a stochastic model for control of chromosome initiation and cell division