Mutational clusters generated by non-processive polymerases: A case study using DNA polymerase betain vitro.

ABSTRACT: Available DNA mutational spectra reveal that the number of mutants with multiple mutations ("multiples") is usually greater than expected from a random distribution of mutations among mutants. These overloads imply the occurrence of non-random clusters of mutations, probably generated during episodes of low-fidelity DNA synthesis. Excess multiples have been reported not only for viruses, bacteria, and eukaryotic cells but also for the DNA polymerases of phages T4 and RB69 in vitro. In the simplest case of a purified polymerase, non-random clusters may be generated by a subfraction of phenotypic variants able to introduce more errors per cycle of DNA synthesis than the normal enzyme. According to this hypothesis, excess multiples are not expected with non-processive polymerases even if they

SUBMITTER: Garcia-Villada L 

PROVIDER: S-EPMC2914196 | biostudies-literature | 2010 Aug

REPOSITORIES: biostudies-literature