Dual roles for DNA sequence identity and the mismatch repair system in the regulation of mitotic crossing-over in yeast.

ABSTRACT: Sequence divergence acts as a potent barrier to homologous recombination; much of this barrier derives from an antirecombination activity exerted by mismatch repair proteins. An inverted repeat assay system with recombination substrates ranging in identity from 74% to 100% has been used to define the relationship between sequence divergence and the rate of mitotic crossing-over in yeast. To elucidate the role of the mismatch repair machinery in regulating recombination between mismatched substrates, we performed experiments in both wild-type and mismatch repair defective strains. We find that a single mismatch is sufficient to inhibit recombination between otherwise identical sequences, and that this inhibition is dependent on the mismatch repair system. Additional mismatches have a cumula

SUBMITTER: Datta A 

PROVIDER: S-EPMC23263 | biostudies-literature | 1997 Sep

REPOSITORIES: biostudies-literature