1iy8

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spinqualitylabelsall models 1iy8, resolution 1.6Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Crystal Structure of Levodione Reductase

Overview

The (6R)-2,2,6-trimethyl-1,4-cyclohexanedione (levodione) reductase (LVR), of the soil isolate bacterium Corynebacterium aquaticum M-13 is a, NAD(H)-linked enzyme that catalyzes reversible oxidoreduction between, (4R)-hydroxy-(6R)-2,2,6-trimethylcyclohexanone (actinol) and levodione., Here the crystal structure of a ternary complex of LVR with NADH and its, inhibitor 2-methyl-2,4-pentanediol has been determined by molecular, replacement and refined at 1.6-A resolution with a crystallographic R, factor of 0.199. The overall structure is similar to those of other, short-chain alcohol dehydrogenase/reductase enzymes. The positions of NADH, and 2-methyl-2,4-pentanediol indicate the binding site of the substrate, and identify residues that are likely to be important in the catalytic, reaction. Modeling of the substrate binding in the active site suggests, that the specificity of LVR is determined by electrostatic interactions, between the negatively charged surface of Glu-103 of LVR and the, positively charged surface on the re side of levodione. Mutant LVR enzymes, in which Glu-103 is substituted with alanine (E103A), glutamine (E103Q), asparagines (E103N), or aspartic acid (E103D) show a 2-6-fold increase in, Km values as compared with wild-type LVR and a much lower enantiomeric, excess of the reaction products (60%) than the wild-type enzyme (95%)., Together, these data indicate that Glu-103 has an important role in, determining the stereospecificity of LVR.

About this Structure

1IY8 is a Single protein structure of sequence from Leifsonia aquatica with NAD and MRD as ligands. Full crystallographic information is available from OCA.

Reference

The crystal structure and stereospecificity of levodione reductase from Corynebacterium aquaticum M-13., Sogabe S, Yoshizumi A, Fukami TA, Shiratori Y, Shimizu S, Takagi H, Nakamori S, Wada M, J Biol Chem. 2003 May 23;278(21):19387-95. Epub 2003 Mar 5. PMID:12621044

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