Strand-specific mismatch correction in nuclear extracts of human and Drosophila melanogaster cell lines.


Journal Article

Nuclear extracts derived from HeLa and Drosophila melanogaster KC cell lines have been found to correct single base-base mispairs within open circular DNA heteroduplexes containing a strand-specific, site-specific incision located 808 base pairs from the mismatch. Correction in both extract systems is strand specific, being highly biased to the incised DNA strand. Different mispairs within a homologous set of heteroduplexes were processed with different efficiencies (G.T greater than G.G approximately equal to A.C greater than C.C), and correction was accompanied by mismatch-dependent DNA synthesis localized to the region spanning the mispair and the strand break, thus demonstrating that mismatch recognition is associated with the repair reaction. Correction of each of these heteroduplexes was abolished by aphidicolin but was relatively insensitive to the presence of high concentrations of ddTTP, indicating probable involvement of alpha and/or delta class DNA polymerase(s). These findings suggest that higher eukaryotic cells possess a general, strand-specific mismatch repair system analogous to the Escherichia coli mutHLS and the Streptococcus pneumoniae hexAB pathways, systems that contribute in a major way to the genetic stability of these bacterial species.

Full Text

Duke Authors

Cited Authors

  • Holmes, J; Clark, S; Modrich, P

Published Date

  • August 1990

Published In

Volume / Issue

  • 87 / 15

Start / End Page

  • 5837 - 5841

PubMed ID

  • 2116007

Pubmed Central ID

  • 2116007

International Standard Serial Number (ISSN)

  • 0027-8424

Digital Object Identifier (DOI)

  • 10.1073/pnas.87.15.5837


  • eng

Conference Location

  • United States