Posttranslational modification of the -encoded subunit of DNA polymerase V regulates its interactions with the processivity clamp

Sutton, M. D.*; Narumi, Issei; Walker, G. C.*

The gene products (PolV) participate in both a DNA damage checkpoint control and translesion DNA synthesis. Interactions of the two gene products, UmuD and UmuD' proteins, with components of the replicative DNA polymerase (PolIII), are important for determining which biological role the gene products will play. We have shown that UmuD possesses a higher affinity for PolIII processivity clamp than does UmuD' because of the N-terminal arm of UmuD, much of which is missing in UmuD'. Futhermore, we identified specific amino acid residues of UmuD that crosslink to with a crosslinker, -azidoiodoacetanilide, defining the domain important for the interaction.