UmuD′ 2 C is an error-prone DNA polymerase, Escherichia coli pol V

• DOI: 10.1073/pnas.96.16.8919
• Publication Date: 2002-07-26T14:38:21Z
• Authors: Mengjia Tang; Xuan Shen; Ekaterina G. Frank; Mike O’Donnell; Roger Woodgate; Myron F. Goodman
• Keywords: Processivity; DNA polymerase II; Primer (cosmetics); DNA clamp; DNA polymerase I; DNA polymerase beta; DNA polymerase delta; SOS response

The damage-inducible UmuD′ and UmuC proteins are required for most SOS mutagenesis in Escherichia coli . Our recent assay to reconstitute this process vitro , using a native 2 C complex, revealed that the highly purified preparation contained DNA polymerase activity. Here we eliminate possibility activity is caused by contaminating show it intrinsic C. E. dinB has recently been shown have (pol IV). We suggest C, fifth discovered be designated as pol V. In presence of RecA, β sliding clamp, γ clamp loading single-stranded binding protein (SSB), V’s “error prone” at both damaged undamaged template sites, catalyzing efficient bypass abasic lesions would otherwise severely inhibit replication III holoenzyme complex (HE). Pol V bypasses site-directed lesion with an efficiency about 100- 150-fold higher than HE. accordance “A-rule,” dAMP preferentially incorporated opposite lesion. A mutant, C104 (D101N), no measurable kinetic analysis shows addition increasing amounts fixed level inhibits bypass, demonstrating enzymes compete free 3′-OH template-primer ends. show, however, despite competition primer-3′-ends, HE can nevertheless interact synergistically stimulate synthesis downstream from