PROSITE documentation PDOC00057
DNA mismatch repair proteins mutL / hexB / PMS1 signature


Mismatch repair contributes to the overall fidelity of DNA replication [1]. 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 evolutionary related. These proteins are:

  • Escherichia coli and Salmonella typhimurium mutL protein [2]. MutL is required for dam-dependent methyl-directed DNA repair.
  • Streptococcus pneumoniae hexB protein [3]. The Hex system is nick directed.
  • Yeast proteins PMS1 and MLH1 [4].
  • Human protein MLH1 [5] which is involved in a form of familial hereditary nonpolyposis colon cancer (HNPCC).

As a signature pattern for this class of mismatch repair proteins we selected a perfectly conserved heptapeptide which is located in the N-terminal section of these proteins.

Last update:

December 2004 / Pattern and text revised.


Technical section

PROSITE method (with tools and information) covered by this documentation:

DNA_MISMATCH_REPAIR_1, PS00058; DNA mismatch repair proteins mutL / hexB / PMS1 signature  (PATTERN)


1AuthorsModrich P.
TitleDNA mismatch correction.
SourceAnnu. Rev. Biochem. 56:435-466(1987).
PubMed ID3304141

2AuthorsMankovich J.A. McIntyre C.A. Walker G.C.
TitleNucleotide sequence of the Salmonella typhimurium mutL gene required for mismatch repair: homology of MutL to HexB of Streptococcus pneumoniae and to PMS1 of the yeast Saccharomyces cerevisiae.
SourceJ. Bacteriol. 171:5325-5331(1989).
PubMed ID2676972

3AuthorsPrudhomme M. Martin B. Mejean V. Claverys J.-P.
TitleNucleotide sequence of the Streptococcus pneumoniae hexB mismatch repair gene: homology of HexB to MutL of Salmonella typhimurium and to PMS1 of Saccharomyces cerevisiae.
SourceJ. Bacteriol. 171:5332-5338(1989).
PubMed ID2676973

4AuthorsProlla T.A. Christie D.M. Liskay R.M.
TitleDual requirement in yeast DNA mismatch repair for MLH1 and PMS1, two homologs of the bacterial mutL gene.
SourceMol. Cell. Biol. 14:407-415(1994).
PubMed ID8264608

5AuthorsBronner C.E. Baker S.M. Morrison P.T. Warren G. Smith L.G. Lescoe M.K. Kane M. Earabino C. Lipford J. Lindblom A.
TitleMutation in the DNA mismatch repair gene homologue hMLH1 is associated with hereditary non-polyposis colon cancer.
SourceNature 368:258-261(1994).
PubMed ID8145827

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