3sbj
From Proteopedia
MutM slanted complex 7
Structural highlights
Function[P84131_GEOSE] Involved in base excision repair of DNA damaged by oxidation or by mutagenic agents. Acts as DNA glycosylase that recognizes and removes damaged bases. Has a preference for oxidized purines, such as 7,8-dihydro-8-oxoguanine (8-oxoG). Has AP (apurinic/apyrimidinic) lyase activity and introduces nicks in the DNA strand. Cleaves the DNA backbone by beta-delta elimination to generate a single-strand break at the site of the removed base with both 3'- and 5'-phosphates (By similarity).[HAMAP-Rule:MF_00103][SAAS:SAAS020629_004_120556] Publication Abstract from PubMedBase excision repair of genotoxic nucleobase lesions in the genome is critically dependent upon the ability of DNA glycosylases to locate rare sites of damage embedded in a vast excess of undamaged DNA, using only thermal energy to fuel the search process. Considerable interest surrounds the question of how DNA glycosylases translocate efficiently along DNA while maintaining their vigilance for target damaged sites. Here, we report the observation of strandwise translocation of 8-oxoguanine DNA glycosylase, MutM, along undamaged DNA. In these complexes, the protein is observed to translocate by one nucleotide on one strand while remaining untranslocated on the complementary strand. We further report that alterations of single base-pairs or a single amino acid substitution (R112A) can induce strandwise translocation. Molecular dynamics simulations confirm that MutM can translocate along DNA in a strandwise fashion. These observations reveal a previously unobserved mode of movement for a DNA-binding protein along the surface of DNA. Strandwise translocation of a DNA glycosylase on undamaged DNA.,Qi Y, Nam K, Spong MC, Banerjee A, Sung RJ, Zhang M, Karplus M, Verdine GL Proc Natl Acad Sci U S A. 2012 Jan 24;109(4):1086-91. Epub 2012 Jan 4. PMID:22219368[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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