Analyses of the interaction between the origin binding domain from simian virus 40 T antigen and single-stranded DNA provide insights into DNA unwinding and initiation of DNA replication.

ABSTRACT: DNA helicases are essential for DNA metabolism; however, at the molecular level little is known about how they assemble or function. Therefore, as a model for a eukaryotic helicase, we are analyzing T antigen (T-ag) the helicase encoded by simian virus 40. In this study, nuclear magnetic resonance (NMR) methods were used to investigate the transit of single-stranded DNA (ssDNA) through the T-ag origin-binding domain (T-ag OBD). When the residues that interact with ssDNA are viewed in terms of the structure of a hexamer of the T-ag OBD, comprised of residues 131 to 260, they indicate that ssDNA passes over one face of the T-ag OBD and then transits through a gap in the open ring structure. The NMR-based conclusions are supported by an analysis of previously described mutations that disrupt

SUBMITTER: Reese DK 

PROVIDER: S-EPMC1676264 | biostudies-literature | 2006 Dec

REPOSITORIES: biostudies-literature