In crystallo observation of three metal ion promoted DNA polymerase misincorporation

• DOI: 10.1038/s41467-022-30005-3
• Publication Date: 2022-04-29T10:05:34Z
• Authors: Caleb Chang; Christie Lee Luo; Yang Gao
• Keywords: Primer (cosmetics); DNA polymerase beta; DNA clamp; Proofreading

Abstract Error-free replication of DNA is essential for life. Despite the proofreading capability several polymerases, intrinsic polymerase fidelity in general much higher than what base-pairing energies can provide. Although researchers have investigated this long-standing question with kinetics, structural determination, and computational simulations, factors that dictate are not fully resolved. Time-resolved crystallography has elucidated correct nucleotide incorporation established a three-metal-ion-dependent catalytic mechanism polymerases. Using X-ray time-resolved crystallography, we visualize complete misincorporation process catalyzed by η. The resulting molecular snapshots suggest primer 3´-OH alignment mediated A-site metal ion binding key step substrate discrimination. Moreover, observe C-site preceded nucleotidyl transfer reaction demonstrate strictly required misincorporation. Our results highlight but separate roles three ions synthesis.