Mistakes occurring during DNA transactions necessarily produce mismatched base pairs.
DNA biosynthetic errors that escape the polymerase editing function yield mispaired bases,
but mismatches also populate a recombination heteroduplex produced by strand transfer
between related sequences that have diverged at the nucleotide level. Study of microbial
systems has demonstrated the importance of mismatch correction in the reversal of such
errors and consequent stabilization of the genome (1–4). 1 Interest in this process has …