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| | <StructureSection load='2qpu' size='340' side='right'caption='[[2qpu]], [[Resolution|resolution]] 1.70Å' scene=''> | | <StructureSection load='2qpu' size='340' side='right'caption='[[2qpu]], [[Resolution|resolution]] 1.70Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[2qpu]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Barley Barley]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2QPU OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2QPU FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[2qpu]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Hordeum_vulgare Hordeum vulgare]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2QPU OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2QPU FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BGC:BETA-D-GLUCOSE'>BGC</scene>, <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=GLC:ALPHA-D-GLUCOSE'>GLC</scene>, <scene name='pdbligand=QPU:1,5-ANHYDRO-4-O-(4,6-DIDEOXY-4-{[(1S,2S,3S,4R,5S,6R)-2,3,4,6-TETRAHYDROXY-5-METHYLCYCLOHEXYL]AMINO}-ALPHA-D-GLUCOPYRANOSYL)-D-GLUCITOL'>QPU</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]] 1.7Å</td></tr> |
| - | <tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=AC1:6-METHYL-5-(4,5,6-TRIHYDROXY-3-HYDROXYMETHYL-CYCLOHEX-2-ENYLAMINO)-TETRAHYDRO-PYRAN-2,3,4-TRIOL'>AC1</scene></td></tr>
| + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=AC1:6-METHYL-5-(4,5,6-TRIHYDROXY-3-HYDROXYMETHYL-CYCLOHEX-2-ENYLAMINO)-TETRAHYDRO-PYRAN-2,3,4-TRIOL'>AC1</scene>, <scene name='pdbligand=BGC:BETA-D-GLUCOSE'>BGC</scene>, <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=GLC:ALPHA-D-GLUCOSE'>GLC</scene>, <scene name='pdbligand=PRD_900022:beta-acarbose'>PRD_900022</scene>, <scene name='pdbligand=QPU:1,5-ANHYDRO-4-O-(4,6-DIDEOXY-4-{[(1S,2S,3S,4R,5S,6R)-2,3,4,6-TETRAHYDROXY-5-METHYLCYCLOHEXYL]AMINO}-ALPHA-D-GLUCOPYRANOSYL)-D-GLUCITOL'>QPU</scene></td></tr> |
| - | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[1ht6|1ht6]], [[1p6w|1p6w]], [[1rpk|1rpk]], [[1rp8|1rp8]], [[1rp9|1rp9]], [[1amy|1amy]], [[2qps|2qps]]</div></td></tr>
| + | |
| - | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">AMY1.1 ([https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=4513 Barley])</td></tr>
| + | |
| - | <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[https://en.wikipedia.org/wiki/Alpha-amylase Alpha-amylase], with EC number [https://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.1 3.2.1.1] </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=2qpu FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2qpu OCA], [https://pdbe.org/2qpu PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2qpu RCSB], [https://www.ebi.ac.uk/pdbsum/2qpu PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2qpu ProSAT]</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=2qpu FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2qpu OCA], [https://pdbe.org/2qpu PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2qpu RCSB], [https://www.ebi.ac.uk/pdbsum/2qpu PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2qpu ProSAT]</span></td></tr> |
| | </table> | | </table> |
| | + | == Function == |
| | + | [https://www.uniprot.org/uniprot/AMY1_HORVU AMY1_HORVU] |
| | == Evolutionary Conservation == | | == Evolutionary Conservation == |
| | [[Image:Consurf_key_small.gif|200px|right]] | | [[Image:Consurf_key_small.gif|200px|right]] |
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| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Alpha-amylase]] | + | [[Category: Hordeum vulgare]] |
| - | [[Category: Barley]]
| + | |
| | [[Category: Large Structures]] | | [[Category: Large Structures]] |
| - | [[Category: Aghajari, N]] | + | [[Category: Aghajari N]] |
| - | [[Category: Haser, R]] | + | [[Category: Haser R]] |
| - | [[Category: Jensen, M H]] | + | [[Category: Jensen MH]] |
| - | [[Category: Tranier, S]] | + | [[Category: Tranier S]] |
| - | [[Category: Alpha beta 8 barrel]]
| + | |
| - | [[Category: Carbohydrate metabolism]]
| + | |
| - | [[Category: Germination]]
| + | |
| - | [[Category: Glycosidase]]
| + | |
| - | [[Category: Hydrolase]]
| + | |
| - | [[Category: Metal-binding]]
| + | |
| - | [[Category: Secreted]]
| + | |
| - | [[Category: Sugar tongs mutant complex]]
| + | |
| Structural highlights
2qpu is a 3 chain structure with sequence from Hordeum vulgare. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
| | Method: | X-ray diffraction, Resolution 1.7Å |
| Ligands: | , , , , , , |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
Function
AMY1_HORVU
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 PubMed
Some starch-degrading enzymes accommodate carbohydrates at sites situated at a certain distance from the active site. In the crystal structure of barley alpha-amylase 1, oligosaccharide is thus bound to the 'sugar tongs' site. This site on the non-catalytic domain C in the C-terminal part of the molecule contains a key residue, Tyr380, which has numerous contacts with the oligosaccharide. The mutant enzymes Y380A and Y380M failed to bind to beta-cyclodextrin-Sepharose, a starch-mimic resin used for alpha-amylase affinity purification. The K(d) for beta-cyclodextrin binding to Y380A and Y380M was 1.4 mm compared to 0.20-0.25 mm for the wild-type, S378P and S378T enzymes. The substitution in the S378P enzyme mimics Pro376 in the barley alpha-amylase 2 isozyme, which in spite of its conserved Tyr378 did not bind oligosaccharide at the 'sugar tongs' in the structure. Crystal structures of both wild-type and S378P enzymes, but not the Y380A enzyme, showed binding of the pseudotetrasaccharide acarbose at the 'sugar tongs' site. The 'sugar tongs' site also contributed importantly to the adsorption to starch granules, as Kd = 0.47 mg.mL(-1) for the wild-type enzyme increased to 5.9 mg.mL(-1) for Y380A, which moreover catalyzed the release of soluble oligosaccharides from starch granules with only 10% of the wild-type activity. beta-cyclodextrin both inhibited binding to and suppressed activity on starch granules for wild-type and S378P enzymes, but did not affect these properties of Y380A, reflecting the functional role of Tyr380. In addition, the Y380A enzyme hydrolyzed amylose with reduced multiple attack, emphasizing that the 'sugar tongs' participates in multivalent binding of polysaccharide substrates.
The 'pair of sugar tongs' site on the non-catalytic domain C of barley alpha-amylase participates in substrate binding and activity.,Bozonnet S, Jensen MT, Nielsen MM, Aghajari N, Jensen MH, Kramhoft B, Willemoes M, Tranier S, Haser R, Svensson B FEBS J. 2007 Oct;274(19):5055-67. Epub 2007 Sep 4. PMID:17803687[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Bozonnet S, Jensen MT, Nielsen MM, Aghajari N, Jensen MH, Kramhoft B, Willemoes M, Tranier S, Haser R, Svensson B. The 'pair of sugar tongs' site on the non-catalytic domain C of barley alpha-amylase participates in substrate binding and activity. FEBS J. 2007 Oct;274(19):5055-67. Epub 2007 Sep 4. PMID:17803687 doi:10.1111/j.1742-4658.2007.06024.x
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