Rowe Researcher: Translesional Synthesis DNA Polymerases

Summer 2012: Structure and Interactions of Translesional Synthesis DNA Polymerases

By Maciej Kosakowski, Dr. Dmitry Korzhnev, Ph.D., Dr. Irena Bezsonova, Ph.D.

During my weeks with the College Summer Fellowship Program at the UConn Health Center, I worked in a structural biology lab in conjunction with the NMR lab under Dr. Korzhnev. I assisted him on his project, which aimed to discover the specific mechanisms behind translesional synthesis DNA polymerases, or TLS polymerases for short.

TLS is a DNA damage tolerance pathway that recruits specific TLS enzymes to the DNA replication machinery, and is used to bypass certain mutations or lesions at the replication fork. This process, however, is highly mutagenic as TLS polymerases have a very low fidelity and incorporate new mutations into the genome. The TLS pathway, therefore, is partially responsible for the proliferation and growth of tumor cells containing highly damaged DNA. Dr. Korzhnev’s lab aims to find a way to inhibit or interfere with the TLS process in order to potentially sensitize cancer cells to chemotherapy.

During my 10 week period in the lab I grew, purified, and expressed multiple protein domains of the Rev1 and PolZ TLS enzymes, as well as PCNA, a ring shaped protein critical to the TLS recruitment pathway. I also had time to titrate two protein domains, hPAD and hUBZ, as well as produce highly purified samples of both proteins for protein NMR spectroscopy and other NMR experiments. It was a pleasure to work in the lab; it was a great learning experience and truly rewarding.

View Matt’s presentation.