title: Quantifying the contributions of base selectivity, proofreading and mismatch repair to nuclear DNA replication in Saccharomyces cerevisiae.
abstract: Mismatches generated during eukaryotic nuclear DNA replication are removed by two evolutionarily conserved error correction mechanisms acting in series, proofreading and mismatch repair (MMR). Defects in both processes are associated with increased susceptibility to cancer. To better understand these processes, we have quantified base selectivity, proofreading and MMR during nuclear DNA replication in Saccharomyces cerevisiae. In the absence of proofreading and MMR, the primary leading and lagging strand replicases, polymerase ɛ and polymerase δ respectively, synthesize DNA in vivo with somewhat different error rates and specificity, and with apparent base selectivity that is more than 100 times higher than measured in vitro. Moreover, leading and lagging strand replication fidelity rely on a different balance between proofreading and MMR. On average, proofreading contributes more to replication fidelity than does MMR, but their relative contributions vary from nearly all proofreading of some mismatches to mostly MMR of other mismatches. Thus accurate replication of the two DNA strands results from a non-uniform and variable balance between error prevention, proofreading and MMR.
authors.affiliation: Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, NIH, DHHS, Research Triangle Park, NC 27709, USA.
authors.forename: Jordan A
authors.initials: JA
authors.lastname: St Charles
authors.affiliation: Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, NIH, DHHS, Research Triangle Park, NC 27709, USA.
authors.forename: Sascha E
authors.initials: SE
authors.lastname: Liberti
authors.affiliation: Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, NIH, DHHS, Research Triangle Park, NC 27709, USA.
authors.forename: Jessica S
authors.initials: JS
authors.lastname: Williams
authors.affiliation: Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, NIH, DHHS, Research Triangle Park, NC 27709, USA.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Lujan
authors.affiliation: Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, NIH, DHHS, Research Triangle Park, NC 27709, USA. Electronic address: kunkel@niehs.nih.gov.
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Kunkel
mesh_terms: D020137:Base Pair Mismatch; D001483:Base Sequence; D053843:DNA Mismatch Repair; D004258:DNA Polymerase III / Q000235:genetics / Q000378:metabolism; D004261:DNA Replication; D008969:Molecular Sequence Data; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D029701:Saccharomyces cerevisiae Proteins; D004258:DNA Polymerase III
keywords: DNA polymerase; Genome stability; Mutation rate; Replication fidelity