Bacterial DNA excision repair pathways

Bacteria are continuously exposed to numerous endogenous and exogenous DNA-damaging agents. To maintain genome integrity and ensure cell survival, bacteria have evolved several DNA repair pathways to correct different types of DNA damage and non-canonical bases, including strand breaks, nucleotide modifications, cross-links, mismatches and ribonucleotide incorporations. Recent advances in genome-wide screens, the availability of thousands of whole-genome sequences and advances in structural biology have enabled the rapid discovery and characterization of novel bacterial DNA repair pathways and new enzymatic activities. In this Review, we discuss recent advances in our understanding of base excision repair and nucleotide excision repair, and we discuss several new repair processes including the EndoMS mismatch correction pathway and the MrfAB excision repair system. To maintain genome integrity and ensure cell survival, bacteria have evolved several DNA repair pathways to repair different types of DNA damage and non-canonical bases, including strand breaks, nucleotide modifications, cross-links, mismatches and ribonucleotide incorporations. In this Review, Wozniak and Simmons provide a contemporary discussion of the excision-based mechanisms bacteria use to repair the diverse set of lesions they encounter.