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| | <StructureSection load='5yeq' size='340' side='right'caption='[[5yeq]], [[Resolution|resolution]] 1.75Å' scene=''> | | <StructureSection load='5yeq' size='340' side='right'caption='[[5yeq]], [[Resolution|resolution]] 1.75Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[5yeq]] is a 2 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5YEQ OCA]. For a <b>guided tour on the structure components</b> use [http://proteopedia.org/fgij/fg.htm?mol=5YEQ FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[5yeq]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Sulfolobus_acidocaldarius Sulfolobus acidocaldarius]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5YEQ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5YEQ FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.75Å</td></tr> |
| - | <tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=MSE:SELENOMETHIONINE'>MSE</scene></td></tr> | + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=MSE:SELENOMETHIONINE'>MSE</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr> |
| - | <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Ketol-acid_reductoisomerase Ketol-acid reductoisomerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.1.1.86 1.1.1.86] </span></td></tr> | + | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=5yeq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5yeq OCA], [https://pdbe.org/5yeq PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5yeq RCSB], [https://www.ebi.ac.uk/pdbsum/5yeq PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5yeq ProSAT]</span></td></tr> |
| - | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://proteopedia.org/fgij/fg.htm?mol=5yeq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5yeq OCA], [http://pdbe.org/5yeq PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=5yeq RCSB], [http://www.ebi.ac.uk/pdbsum/5yeq PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=5yeq ProSAT]</span></td></tr> | + | |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/A0A0U3H6N8_9CREN A0A0U3H6N8_9CREN]] Involved in the biosynthesis of branched-chain amino acids (BCAA). Catalyzes an alkyl-migration followed by a ketol-acid reduction of (S)-2-acetolactate (S2AL) to yield (R)-2,3-dihydroxy-isovalerate. In the isomerase reaction, S2AL is rearranged via a Mg-dependent methyl migration to produce 3-hydroxy-3-methyl-2-ketobutyrate (HMKB). In the reductase reaction, this 2-ketoacid undergoes a metal-dependent reduction by NADPH to yield (R)-2,3-dihydroxy-isovalerate.[HAMAP-Rule:MF_00435] | + | [https://www.uniprot.org/uniprot/ILVC_SULAC ILVC_SULAC] Involved in the biosynthesis of branched-chain amino acids (BCAA). Catalyzes an alkyl-migration followed by a ketol-acid reduction of (S)-2-acetolactate (S2AL) to yield (R)-2,3-dihydroxy-isovalerate. In the isomerase reaction, S2AL is rearranged via a Mg-dependent methyl migration to produce 3-hydroxy-3-methyl-2-ketobutyrate (HMKB). In the reductase reaction, this 2-ketoacid undergoes a metal-dependent reduction by NADPH to yield (R)-2,3-dihydroxy-isovalerate.[HAMAP-Rule:MF_00435] |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
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| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Ketol-acid reductoisomerase]] | |
| | [[Category: Large Structures]] | | [[Category: Large Structures]] |
| - | [[Category: Chen, C Y]] | + | [[Category: Sulfolobus acidocaldarius]] |
| - | [[Category: Chiang, C H]] | + | [[Category: Chen CY]] |
| - | [[Category: Horng, J C]] | + | [[Category: Chiang CH]] |
| - | [[Category: Huang, C H]] | + | [[Category: Horng JC]] |
| - | [[Category: Ko, T P]] | + | [[Category: Huang CH]] |
| - | [[Category: Lin, B L]] | + | [[Category: Ko TP]] |
| - | [[Category: Lin, K F]] | + | [[Category: Lin BL]] |
| - | [[Category: Tsai, M D]] | + | [[Category: Lin KF]] |
| - | [[Category: Acid tolerant enzyme]]
| + | [[Category: Tsai MD]] |
| - | [[Category: Ahir]]
| + | |
| - | [[Category: Bcaa]]
| + | |
| - | [[Category: Biofuel]]
| + | |
| - | [[Category: Branched-chain amino acid]]
| + | |
| - | [[Category: Isomerase]]
| + | |
| - | [[Category: Knot domain]]
| + | |
| - | [[Category: Metal ion cofactor]]
| + | |
| - | [[Category: Nadh]]
| + | |
| - | [[Category: Nadph]]
| + | |
| - | [[Category: Reductase]]
| + | |
| Structural highlights
Function
ILVC_SULAC Involved in the biosynthesis of branched-chain amino acids (BCAA). Catalyzes an alkyl-migration followed by a ketol-acid reduction of (S)-2-acetolactate (S2AL) to yield (R)-2,3-dihydroxy-isovalerate. In the isomerase reaction, S2AL is rearranged via a Mg-dependent methyl migration to produce 3-hydroxy-3-methyl-2-ketobutyrate (HMKB). In the reductase reaction, this 2-ketoacid undergoes a metal-dependent reduction by NADPH to yield (R)-2,3-dihydroxy-isovalerate.[HAMAP-Rule:MF_00435]
Publication Abstract from PubMed
Ketol-acid reductoisomerase (KARI) is a bifunctional enzyme in the second step of branched-chain amino acids biosynthetic pathway. Most KARIs prefer NADPH as a cofactor. However, KARI with a preference for NADH is desirable in industrial applications including anaerobic fermentation for the production of branched-chain amino acids or biofuels. Here, we characterize a thermoacidophilic archaeal Sac-KARI from Sulfolobus acidocaldarius and present its crystal structure at a 1.75-A resolution. By comparison with other holo-KARI structures, one sulphate ion is observed in each binding site for the 2'-phosphate of NADPH, implicating its NADPH preference. Sac-KARI has very high affinity for NADPH and NADH, with K M values of 0.4 muM for NADPH and 6.0 muM for NADH, suggesting that both are good cofactors at low concentrations although NADPH is favoured over NADH. Furthermore, Sac-KARI can catalyze 2(S)-acetolactate (2S-AL) with either cofactor from 25 to 60 degrees C, but the enzyme has higher activity by using NADPH. In addition, the catalytic activity of Sac-KARI increases significantly with elevated temperatures and reaches an optimum at 60 degrees C. Bi-cofactor utilization and the thermoactivity of Sac-KARI make it a potential candidate for use in metabolic engineering or industrial applications under anaerobic or harsh conditions.
NADH/NADPH bi-cofactor-utilizing and thermoactive ketol-acid reductoisomerase from Sulfolobus acidocaldarius.,Chen CY, Ko TP, Lin KF, Lin BL, Huang CH, Chiang CH, Horng JC Sci Rep. 2018 May 8;8(1):7176. doi: 10.1038/s41598-018-25361-4. PMID:29739976[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Chen CY, Ko TP, Lin KF, Lin BL, Huang CH, Chiang CH, Horng JC. NADH/NADPH bi-cofactor-utilizing and thermoactive ketol-acid reductoisomerase from Sulfolobus acidocaldarius. Sci Rep. 2018 May 8;8(1):7176. doi: 10.1038/s41598-018-25361-4. PMID:29739976 doi:http://dx.doi.org/10.1038/s41598-018-25361-4
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