Brooks P, Dohet C, Almouzni G, Méchali M, Radman M
Institut Jacques Monod. Centre National de la Recherche Scientifique, Paris, France.
Proc Natl Acad Sci U S A. 1989 Jun;86(12):4425-9. doi: 10.1073/pnas.86.12.4425.
Repair of heteroduplex DNA containing G.T or A.C mismatches or containing two tandem unpaired bases occurred in vitro with Xenopus egg extracts as detected by a physical assay. The repair was accompanied by a mismatch-stimulated and mismatch-localized DNA synthesis. Repaired molecules, separated from unrepaired molecules, showed a 20- to 100-fold increase in DNA synthesis in the region of the mismatch compared to regions distant from the mismatch. The remaining unrepaired heteroduplex DNA included molecules that also displayed mismatch-stimulated DNA synthesis in the mismatch-proximal regions. These may represent intermediates in the repair process. The patterns of DNA synthesis suggest that repair begins at some distance from the mismatch and that as much as 1 kilobase or more can be involved in the mismatch-stimulated synthesis.
