title: Dual daughter strand incision is processive and increases the efficiency of DNA mismatch repair.
abstract: DNA mismatch repair (MMR) is an evolutionarily-conserved process responsible for the repair of replication errors. In Escherichia coli, MMR is initiated by MutS and MutL, which activate MutH to incise transiently-hemimethylated GATC sites. MMR efficiency depends on the distribution of these GATC sites. To understand which molecular events determine repair efficiency, we quantitatively studied the effect of strand incision on unwinding and excision activity. The distance between mismatch and GATC site did not influence the strand incision rate, and an increase in the number of sites enhanced incision only to a minor extent. Two GATC sites were incised by the same activated MMR complex in a processive manner, with MutS, the closed form of MutL and MutH displaying different roles. Unwinding and strand excision were more efficient on a substrate with two nicks flanking the mismatch, as compared to substrates containing a single nick or two nicks on the same side of the mismatch. Introduction of multiple nicks by the human MutLα endonuclease also contributed to increased repair efficiency. Our data support a general model of prokaryotic and eukaryotic MMR in which, despite mechanistic differences, mismatch-activated complexes facilitate efficient repair by creating multiple daughter strand nicks.
authors.affiliation: Department of Molecular Genetics, Cancer Genomics Netherlands, Erasmus Medical Center Rotterdam, 3015 AA Rotterdam,The Netherlands.
authors.forename: Nicolaas
authors.initials: N
authors.lastname: Hermans
authors.affiliation: Department of Molecular Genetics, Cancer Genomics Netherlands, Erasmus Medical Center Rotterdam, 3015 AA Rotterdam,The Netherlands.
authors.forename: Charlie
authors.initials: C
authors.lastname: Laffeber
authors.affiliation: Department of Molecular Genetics, Cancer Genomics Netherlands, Erasmus Medical Center Rotterdam, 3015 AA Rotterdam,The Netherlands.
authors.forename: Michele
authors.initials: M
authors.lastname: Cristovão
authors.affiliation: Institute of Molecular Cancer Research of the University of Zurich and ETH Zurich, Winterthurerstrasse 190, CH 8057 Zurich, Switzerland.
authors.forename: Mariela
authors.initials: M
authors.lastname: Artola-Borán
authors.affiliation: Department of Molecular Genetics, Cancer Genomics Netherlands, Erasmus Medical Center Rotterdam, 3015 AA Rotterdam,The Netherlands.
authors.forename: Yannicka
authors.initials: Y
authors.lastname: Mardenborough
authors.affiliation: Department of Molecular Genetics, Cancer Genomics Netherlands, Erasmus Medical Center Rotterdam, 3015 AA Rotterdam,The Netherlands.
authors.forename: Pauline
authors.initials: P
authors.lastname: Ikpa
authors.affiliation: Department of Molecular Genetics, Cancer Genomics Netherlands, Erasmus Medical Center Rotterdam, 3015 AA Rotterdam,The Netherlands.
authors.forename: Aruna
authors.initials: A
authors.lastname: Jaddoe
authors.affiliation: Division of Biochemistry and Center for Biomedical Genetics, Netherlands Cancer Institute, 1006 BE Amsterdam, The Netherlands.
authors.forename: Herrie H K
authors.initials: HH
authors.lastname: Winterwerp
authors.affiliation: Department of Molecular Genetics, Cancer Genomics Netherlands, Erasmus Medical Center Rotterdam, 3015 AA Rotterdam,The Netherlands Department of Radiation Oncology, Erasmus Medical Center Rotterdam, 3015 CE Rotterdam, The Netherlands.
authors.forename: Claire
authors.initials: C
authors.lastname: Wyman
authors.affiliation: Institute of Molecular Cancer Research of the University of Zurich and ETH Zurich, Winterthurerstrasse 190, CH 8057 Zurich, Switzerland.
authors.forename: Josef
authors.initials: J
authors.lastname: Jiricny
authors.affiliation: Department of Molecular Genetics, Cancer Genomics Netherlands, Erasmus Medical Center Rotterdam, 3015 AA Rotterdam,The Netherlands Department of Radiation Oncology, Erasmus Medical Center Rotterdam, 3015 CE Rotterdam, The Netherlands.
authors.forename: Roland
authors.initials: R
authors.lastname: Kanaar
authors.affiliation: Institute for Biochemistry, Justus-Liebig-University, D-35392 Giessen, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Friedhoff
authors.affiliation: Department of Molecular Genetics, Cancer Genomics Netherlands, Erasmus Medical Center Rotterdam, 3015 AA Rotterdam,The Netherlands Department of Radiation Oncology, Erasmus Medical Center Rotterdam, 3015 CE Rotterdam, The Netherlands j.lebbink@erasmusmc.nl.
authors.forename: Joyce H G
authors.initials: JH
authors.lastname: Lebbink
mesh_terms: D020137:Base Pair Mismatch / Q000235:genetics; D001483:Base Sequence; D019175:DNA Methylation / Q000235:genetics; D053843:DNA Mismatch Repair; D004261:DNA Replication; D004926:Escherichia coli / Q000235:genetics; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D008954:Models, Biological; D011487:Protein Conformation
chemical_list: D029968:Escherichia coli Proteins