Mismatch repair contributes to the overall fidelity of DNA replication []. It involves the correction of mismatched base pairs that have been missed by the proofreading element of the DNA polymerase complex. The sequence of some proteins involved in mismatch repair in different organisms have been found to be evolutionarily related. These proteins include:Escherichia coli and Salmonella typhimurium mutL protein []. MutL is required for dam-dependent methyl-directed DNA repair.Streptococcus pneumoniae hexB protein []. The Hex system is nick directed.Yeast proteins PMS1 and MLH1 [].Human protein MLH1 []which is involved in a form of familial hereditary nonpolyposis colon cancer (HNPCC).This entry represents a perfectly conserved heptapeptide which is located in the N-terminal sectionof these proteins.
