1iy8
From Proteopedia
(New page: 200px<br /><applet load="1iy8" size="450" color="white" frame="true" align="right" spinBox="true" caption="1iy8, resolution 1.6Å" /> '''Crystal Structure of ...) |
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| - | [[Image:1iy8.jpg|left|200px]]<br /><applet load="1iy8" size=" | + | [[Image:1iy8.jpg|left|200px]]<br /><applet load="1iy8" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1iy8, resolution 1.6Å" /> | caption="1iy8, resolution 1.6Å" /> | ||
'''Crystal Structure of Levodione Reductase'''<br /> | '''Crystal Structure of Levodione Reductase'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The (6R)-2,2,6-trimethyl-1,4-cyclohexanedione (levodione) reductase (LVR) | + | 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== | ==About this Structure== | ||
| - | 1IY8 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Leifsonia_aquatica Leifsonia aquatica] with NAD and MRD as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1IY8 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Leifsonia_aquatica Leifsonia aquatica] with <scene name='pdbligand=NAD:'>NAD</scene> and <scene name='pdbligand=MRD:'>MRD</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1IY8 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: oxidoreductase]] | [[Category: oxidoreductase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:16:59 2008'' |
Revision as of 11:17, 21 February 2008
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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 and 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
Page seeded by OCA on Thu Feb 21 13:16:59 2008
Categories: Leifsonia aquatica | Single protein | Fukami, T. | Shiratori, Y. | Sogabe, S. | Wada, M. | Yoshizumi, A. | MRD | NAD | Oxidoreductase
