Preferential D-loop extension by a translesion DNA polymerase underlies error-prone recombination

Genetic evidence has implicated the SOS-induced translesion DNA polymerase DinB (Pol IV) in error-prone recombination. Now biochemical analyses show that Pol IV outcompetes high-fidelity polymerases during the extension of D-loop recombination intermediates under SOS response conditions, providing new insight into the mechanism of stress-induced mutations in Escherichia coli.