Alekseeva IV, Bakman AS, Iakovlev DA, Kuznetsov NA, Fedorova OS. [Comparative Analysis of the Activity of the Polymorphic Variants of Human Uracil-DNA-Glycosylases SMUG1 and MBD4].
Mol Biol (Mosk) 2021;
55:277-288. [PMID:
33871441 DOI:
10.31857/s0026898421020026]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 10/26/2020] [Indexed: 06/12/2023]
Abstract
The human N-glycosylases SMUG1 and MBD4 catalyze the removal of uracil residues from DNA resulting from cytosine deamination or replication errors. For polymorphic variants of SMUG1 (G90C, P240H, N244S, N248Y) and the MBD4^(cat) catalytic domain (S470L, G507S, R512W, H557D), the structures of enzyme-substrate complexes were obtained by molecular dynamic simulation. It was experimentally found that the SNP variants of SMUG1, N244S and N248Y, had increased catalytic activity compared to the wild-type enzyme, probably due to the acceleration of the dissociation of the enzyme-product complex and an increase in the enzyme turnover rate. All other SNP variants of SMUG1 (G90C, P240H) and MBD4^(cat), in which amino acid substitutions disrupted the substrate binding region and/or active site, had significantly lower catalytic activity than the wild-type enzymes.
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