BacterialDNAPolymerases, Chemistry of

Abstract

All DNA polymerases share a common two‐metal ion catalyzed chemistry of nucleotide incorporation. Structure analysis, however, suggests that DNA polymerases share one of two different ancestors, which converged to employ the same mechanism. Escherichia coli , the prototypical bacterium, encodes five different DNA polymerases. The chromosomal replicase functions closely with clamps, clamp‐loaders, and other proteins. Oxidative damage to DNA during normal cell growth requires interplay among the several distinct DNA polymerases, which enable the replicase to circumvent these obstacles and complete chromosomal replication. Additional processes involving DNA polymerases are brought into action during heightened levels of DNA damage. We review here DNA polymerase structure, catalytic mechanism, and several pathways in which various bacterial DNA polymerases act.