The E. coli single stranded DNA binding protein SSB interacts with the UmuD polymerase manager protein (735.7)

Abstract

Escherichia coli single‐stranded DNA binding protein (SSB) binds to and protects the ssDNA present in various DNA processing mechanisms. It has been shown that SSB inhibits replication by binding to the C‐terminal domain of the α subunit of DNA polymerase III, the main replicative polymerase in E. coli. Though this interaction between SSB and α occurs through the globular N‐terminal domain of SSB, it has also been shown that SSB serves as a hub for different proteins involved in DNA processing pathways, through interaction with its C‐terminal tail. One such protein is DNA polymerase V, a Y‐family polymerase encoded by the umuDC genes. The interactions between UmuC, the polymerase subunit of DNA pol V, and SSB have been shown to increase access to the primer termini, and thereby increase the efficiency of pol V. In addition to the previously observed interaction of UmuC with SSB (Arad 2008 JBC 283:8274), we have determined that UmuD also physically interacts with SSB, which is weakened by the SSB‐113 (P177S) mutation. We are currently further characterizing this interaction. Supported by NSF and the American Cancer Society.Grant Funding Source: NSF and American Cancer Society