Regulation of error prone DNA polymerases in DNA replication and translesion synthesis
We are interested in how cells regulate the access of low-fidelity polymerases to the replication fork as their misuse leads to genome instability. In translesion synthesis (TLS), error-prone TLS polymerases are recruited to sites of DNA damage to carry out strand extension over DNA lesions that block the progress of the replisome. Using the E. coli replisome as a model system, we have demonstrated that we can reconstitute translesion synthesis at site-specific DNA lesions and observe polymerase exchange on individual DNAs. Using this approach we have shown that the translesion polymerases Pol IV and Pol II can bind the processivity clamp beta, allowing for rapid lesion bypass. In current work we are extending these studies to the fully reconstituted bacterial replisome and in live cells.