4dxh | pdb_00004dxh

Horse liver alcohol dehydrogenase complexed with NAD+ and 2,2,2-trifluoroethanol

spinqualitylabelsall models 4dxh, resolution 1.12Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4dxh is a 2 chain structure with sequence from Equus caballus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: ETF, MRD, NAJ, ZN Related: 4dwv, 1hld, 1n92, 3oq6, 1p1r Activity: Alcohol dehydrogenase, with EC number 1.1.1.1 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Publication Abstract from PubMed Structures of horse liver alcohol dehydrogenase complexed with NAD(+) and unreactive substrate analogues, 2,2,2-trifluoroethanol or 2,3,4,5,6-pentafluorobenzyl alcohol, were determined at 100 K at 1.12 or 1.14 A resolution, providing estimates of atomic positions with overall errors of approximately 0.02 A, the geometry of ligand binding, descriptions of alternative conformations of amino acid residues and waters, and evidence of a strained nicotinamide ring. The four independent subunits from the two homodimeric structures differ only slightly in the peptide backbone conformation. Alternative conformations for amino acid side chains were identified for 50 of the 748 residues in each complex, and Leu-57 and Leu-116 adopt different conformations to accommodate the different alcohols at the active site. Each fluoroalcohol occupies one position, and the fluorines of the alcohols are well-resolved. These structures closely resemble the expected Michaelis complexes with the pro-R hydrogens of the methylene carbons of the alcohols directed toward the re face of C4N of the nicotinamide rings with a C-C distance of 3.40 A. The oxygens of the alcohols are ligated to the catalytic zinc at a distance expected for a zinc alkoxide (1.96 A) and participate in a low-barrier hydrogen bond (2.52 A) with the hydroxyl group of Ser-48 in a proton relay system. As determined by X-ray refinement with no restraints on bond distances and planarity, the nicotinamide rings in the two complexes are slightly puckered (quasi-boat conformation, with torsion angles of 5.9 degrees for C4N and 4.8 degrees for N1N relative to the plane of the other atoms) and have bond distances that are somewhat different compared to those found for NAD(P)(+). It appears that the nicotinamide ring is strained toward the transition state on the path to alcohol oxidation. Atomic-Resolution Structures of Horse Liver Alcohol Dehydrogenase with NAD(+) and Fluoroalcohols Define Strained Michaelis Complexes.,Plapp BV, Ramaswamy S Biochemistry. 2012 May 15;51(19):4035-48. Epub 2012 May 1. PMID:22531044 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Alcohol dehydrogenase 3D structures

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