Competitive fitness during feast and famine: how SOS DNA polymerases influence physiology and evolution in Escherichia coli.

ABSTRACT: Escherichia coli DNA polymerases (Pol) II, IV, and V serve dual roles by facilitating efficient translesion DNA synthesis while simultaneously introducing genetic variation that can promote adaptive evolution. Here we show that these alternative polymerases are induced as cells transition from exponential to long-term stationary-phase growth in the absence of induction of the SOS regulon by external agents that damage DNA. By monitoring the relative fitness of isogenic mutant strains expressing only one alternative polymerase over time, spanning hours to weeks, we establish distinct growth phase-dependent hierarchies of polymerase mutant strain competitiveness. Pol II confers a significant physiological advantage by facilitating efficient replication and creating genetic diversity during p

SUBMITTER: Corzett CH 

PROVIDER: S-EPMC3664851 | biostudies-literature | 2013 Jun

REPOSITORIES: biostudies-literature