Memorial Sloan-Kettering Cancer Center researchers have gained new insight into the mechanism by which a cell copies its genetic material prior to cell division, a process known as DNA replication. Conducted by molecular biology graduate student Ryan C. Heller and Kenneth J. Marians, Chairman of the Molecular Biology Program, the research was published in the February issue of Nature. [PubMed Abstract]
During DNA replication, the progression of a replication fork -- the point at which the two strands of a chromosome are separated and copied -- can be blocked by a variety of obstructions. Reactivating an arrested fork is crucial to an organism's survival. Studying reactivation pathways using purified protein components from the bacterium E. coli, the researchers demonstrated that replication can be restarted at a point past an unrepaired block, allowing DNA replication to proceed by a new initiation event.
The study's observations reveal a mechanism during replication that bypasses DNA damage, helping to ensure genome stability by allowing DNA replication to be completed in a timely fashion and by allowing for more time to repair the DNA damage by accurate repair processes.
