This applicant will study DNA mismatch repair, which contributes to maintenance of genetic stability by eliminating DNA biosynthetic errors and by blocking recombination between DNA sequences that differ by more than 1% at the nucleotide level. Specifically, he plans to work on the biochemical basis for the anti-recombination associated with mismatch corrections in E. coli. This work is planned to take place in the laboratory of Dr. Paul Modrich at Duke University.