E. Evans et al., The Saccharomyces cerevisiae Msh2 mismatch repair protein localizes to recombination intermediates in vivo, MOL CELL, 5(5), 2000, pp. 789-799
Mismatch repair proteins act during double-strand break repair (DSBR) to co
rrect mismatches in heteroduplex DNA, to suppress recombination between div
ergent sequences, and to promote removal of nonhomologous DNA at DSB ends.
We investigated yeast Msh2p association with recombination intermediates in
vivo using chromatin immunoprecipitation. During DSBR involving nonhomolog
ous ends, Msh2p localized strongly to recipient and donor sequences. Locali
zation required Msh3p and was greatly reduced in rad50 Delta strains. Minim
al localization of Msh2p was observed during fully homologous repair, but t
his was increased in rad52 Delta strains. These findings argue that Msh2p-M
sh3p associates with intermediates early in DSBR to participate in the reje
ction of homeologous pairing and to stabilize nonhomologous tails for cleav
age by Rad1p-Rad10p endonuclease.