The SOS Error-Prone DNA Polymerase V Mutasome and β-Sliding Clamp Acting in Concert on Undamaged DNA and during Translesion Synthesis.

摘要: In the mid 1970s, Miroslav Radman and Evelyn Witkin proposed that Escherichia coli must encode a specialized error-prone DNA polymerase (pol) to account for 100-fold increase in mutations accompanying induction of SOS regulon. By late 1980s, genetic studies showed mutagenesis required presence two "UV mutagenesis" genes, umuC umuD, along with recA. Guided by genetics, decades biochemical have defined predicted as an activated complex these three gene products, assembled mutasome, pol V Mut = UmuD'2C-RecA-ATP. Here, we explore role β-sliding processivity clamp on efficiency Mut-catalyzed synthesis undamaged during translesion (TLS). Primer elongation efficiencies TLS were strongly enhanced β. The results suggest β may stabilizing roles: its canonical tethering at primer-3'-terminus, possible second inhibiting Mut's ATPase reduce rate mutasome-DNA dissociation. identification umuC, recA homologs numerous strains pathogenic bacteria plasmids will ensure long productive continuation journey initiated Witkin.