8i1i
From Proteopedia
Crystal structure of human MTH1(G2K/D120N mutant) in complex with 2-oxo-dATP at pH 7.7
Structural highlights
Function8ODP_HUMAN Antimutagenic. Acts as a sanitizing enzyme for oxidized nucleotide pools, thus suppressing cell dysfunction and death induced by oxidative stress. Hydrolyzes 8-oxo-dGTP, 8-oxo-dATP and 2-OH-dATP, thus preventing misincorporation of oxidized purine nucleoside triphosphates into DNA and subsequently preventing A:T to C:G and G:C to T:A transversions. Able to hydrolyze also the corresponding ribonucleotides, 2-OH-ATP, 8-oxo-GTP and 8-oxo-ATP.[1] [2] [3] [4] [5] Publication Abstract from PubMedHuman MutT homolog 1 (MTH1), also known as Nudix-type motif 1 (NUDT1), hydrolyzes 8-oxo-dGTP and 2-oxo-dATP with broad substrate recognition and has attracted attention in anticancer therapeutics. Previous studies on MTH1 have proposed that the exchange of the protonation state between Asp119 and Asp120 is essential for the broad substrate recognition of MTH1. To understand the relationship between protonation states and substrate binding, we determined the crystal structures of MTH1 at pH 7.7-9.7. With increasing pH, MTH1 gradually loses its substrate-binding ability, indicating that Asp119 is deprotonated at pH 8.0-9.1 in 8-oxo-dGTP recognition and Asp120 is deprotonated at pH 8.6-9.7 in 2-oxo-dATP recognition. These results confirm that MTH1 recognizes 8-oxo-dGTP and 2-oxo-dATP by exchanging the protonation state between Asp119 and Asp120 with higher pK(a) . Protonation states of Asp residues in the human Nudix hydrolase MTH1 contribute to its broad substrate recognition.,Nakamura T, Koga-Ogawa Y, Fujimiya K, Chirifu M, Goto M, Ikemizu S, Nakabeppu Y, Yamagata Y FEBS Lett. 2023 Jul;597(13):1770-1778. doi: 10.1002/1873-3468.14611. Epub 2023 , Mar 23. PMID:36914375[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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