3h4l
Crystal Structure of N terminal domain of a DNA repair proteinCrystal Structure of N terminal domain of a DNA repair protein
Structural highlights
FunctionPMS1_YEAST Required for DNA mismatch repair (MMR), correcting base-base mismatches and insertion-deletion loops (IDLs) resulting from DNA replication, DNA damage or from recombination events between non-identical sequences during meiosis. Component of the MutLalpha heterodimer that forms a ternary complex with the MutS heterodimers, which initially recognize the DNA mismatches. This complex is thought to be responsible for directing the downsteam MMR events, including strand discrimination, excision, and resynthesis. Plays a major role in maintaining the genetic stability of simple sequence repeats and in the repair of heteroduplex sites present in meiotic recombination intermediates.[1] [2] [3] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedSaccharomyces cerevisiae MutLalpha is a heterodimer of Mlh1 and Pms1 that participates in DNA mismatch repair (MMR). Both proteins have weakly conserved C-terminal regions (CTDs), with the CTD of Pms1 harboring an essential endonuclease activity. These proteins also have conserved N-terminal domains (NTDs) that bind and hydrolyze ATP and bind to DNA. To better understand Pms1 functions and potential interactions with DNA and/or other proteins, we solved the 2.5A crystal structure of yeast Pms1 (yPms1) NTD. The structure is similar to the homologous NTDs of Escherichia coli MutL and human PMS2, including the site involved in ATP binding and hydrolysis. The structure reveals a number of conserved, positively charged surface residues that do not interact with other residues in the NTD and are therefore candidates for interactions with DNA, with the CTD and/or with other proteins. When these were replaced with glutamate, several replacements resulted in yeast strains with elevated mutation rates. Two replacements also resulted in NTDs with decreased DNA binding affinity in vitro, suggesting that these residues contribute to DNA binding that is important for mismatch repair. Elevated mutation rates also resulted from surface residue replacements that did not affect DNA binding, suggesting that these conserved residues serve other functions, possibly involving interactions with other MMR proteins. Functional residues on the surface of the N-terminal domain of yeast Pms1.,Arana ME, Holmes SF, Fortune JM, Moon AF, Pedersen LC, Kunkel TA DNA Repair (Amst). 2010 Apr 4;9(4):448-57. PMID:20138591[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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