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Updated: Aug 11, 2026

Mutagenesis and Functional Selection Protocols for Directed Evolution of Proteins in E. coli
Published on: March 16, 2011
DNA polymerase V-dependent mutator activity in an SOS-induced Escherichia coli strain with a temperature-sensitive
Andrew R Timms1, Bryn A Bridges
1MRC Cell Mutation Unit, University of Sussex, Falmer, BN1 9RR, Brighton, UK
Abstract:
The temperature-sensitive DNA polymerase III (Pol III) encoded by the dnaE486 allele confers a spontaneous mutator activity in SOS-induced bacteria that is largely dependent upon DNA polymerase V (Pol V), encoded by umuD, C. This mutator activity is influenced by the defective proof-reading sub-unit of Pol III encoded by the dnaQ905 (mutD5) allele arguing that Pol V is most likely fixing mutations arising from mismatched primer termini produced by Pol III(486). The size of the dnaQ effect is, however, modest leaving open the possibility that Pol V may be responsible for some of the mutator effect by engaging in bursts of processive activity.
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