1mut
NMR STUDY OF MUTT ENZYME, A NUCLEOSIDE TRIPHOSPHATE PYROPHOSPHOHYDROLASE
Structural highlights
FunctionMUTT_ECOLI Involved in the GO system responsible for removing an oxidatively damaged form of guanine (7,8-dihydro-8-oxoguanine) from DNA and the nucleotide pool. 8-oxo-dGTP is inserted opposite dA and dC residues of template DNA with almost equal efficiency thus leading to A.T to G.C transversions. MutT specifically degrades 8-oxo-dGTP to the monophosphate.[1] [2] 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 PubMedThe MutT enzyme (129 residues) catalyzes the hydrolysis of normal and mutagenic nucleoside triphosphates, such as 8-oxo-dGTP, by substitution at the rarely attacked beta-P, to yield NMP and pyrophosphate. Previous heteronuclear NMR studies of MutT have shown the secondary structure to consist of a five-stranded mixed beta-sheet connected by the loop I-alpha-helix I--loop II motif, by two tight turns, and by loop III, and terminated by loop IV--alpha-helix II [Abeygunawardana et al. (1993) Biochemistry 32, 13071-13080; Weber et al. (1993) Biochemistry 32, 13081-13087). Complete side-chain assignments of 1H and 13C resonances have now been made by 3D C(CO)NH and HCCH-TOCSY experiments. A total of 1461 interproton proximities (11 per residue), obtained by 3D 15N-resolved NOESY-HSQC and 3D 13C-resolved NOESY-HSQC spectra, including 372 long-range NOEs, as well as 65 dihedral angle (phi) restraints and 34 backbone hydrogen bond restraints were used to determine the tertiary structure of MutT by distance geometry, simulated annealing, and energy minimization with the program X-PLOR. The structure is globular and compact with the parallel portion of the beta-sheet sandwiched between the two alpha-helices, forming an alpha+beta fold. The essential divalent cation has previously been shown to bind near residues Gly-37, Gly-38, Lys-39, and Glu-57, and nucleotides have been shown to bind near residues Leu-54 and Val-58 by NMR relaxation methods [Frick et al. (1995) Biochemistry 34, 5577-5586].(ABSTRACT TRUNCATED AT 250 WORDS) Solution structure of the MutT enzyme, a nucleoside triphosphate pyrophosphohydrolase.,Abeygunawardana C, Weber DJ, Gittis AG, Frick DN, Lin J, Miller AF, Bessman MJ, Mildvan AS Biochemistry. 1995 Nov 21;34(46):14997-5005. PMID:7578113[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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