Efficient Extension of Slipped DNA Intermediates by DinB Is Required To Escape Primer Template Realignment by DnaQ

Abstract

ABSTRACT We show that Escherichia coli DinB polymerase, which creates single-base deletions, prefers to extend slipped DNA substrates with the skipped base at the −4 position. A DinB(Y79L) variant, which extends these substrates less efficiently in vitro , allows the proofreading function of polymerase III to reverse their formation in vivo .