View source for 7taa


==FAMILY 13 ALPHA AMYLASE IN COMPLEX WITH ACARBOSE==
<StructureSection load='7taa' size='340' side='right'caption='[[7taa]], [[Resolution|resolution]] 1.98&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[7taa]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Aspergillus_oryzae Aspergillus oryzae]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7TAA OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7TAA FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.98&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ABC:MODIFIED+ACARBOSE+HEXASACCHARIDE'>ABC</scene>, <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene></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=7taa FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7taa OCA], [https://pdbe.org/7taa PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7taa RCSB], [https://www.ebi.ac.uk/pdbsum/7taa PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7taa ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/AMYA1_ASPOR AMYA1_ASPOR] 
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/ta/7taa_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=7taa ConSurf].
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== Publication Abstract from PubMed ==
The three-dimensional structure of the Aspergillus oryzae alpha-amylase (TAKA-amylase), in complex with the inhibitor acarbose, has been determined by X-ray crystallography at a resolution of 1. 98 A. The tetrasaccharide inhibitor is present as a hexasaccharide presumably resulting from a transglycosylation event. The hexasaccharide occupies the -3 to +3 subsites of the enzyme, consistent with the known number of subsites determined by kinetic studies, with the acarbose unit itself in the -1 to +3 subsites of the enzyme. The transition state mimicking unsaturated pseudo-saccharide occupies the -1 subsite as expected and is present in a distorted 2H3 half-chair conformation. Careful refinement plus extremely well-resolved unbiased electron density suggest that the hexasaccharide represents a genuine transglycosylation product, but the possibility that this apparent species results from an overlapping network of tetrasaccharides is also discussed. Catalysis by alpha-amylase involves the hydrolysis of the alpha-1,4 linkages in amylose with a net retention of the anomeric configuration, via a double-displacement mechanism, as originally outlined by Koshland [Koshland, D. E. (1953) Biol. Rev. 28, 416-336]. The enzymatic acid/base and nucleophile, residues Glu230 and Asp206, respectively, are appropriately positioned for catalysis in this complex, and the hexasaccharide species allows mapping of all the noncovalent interactions between protein and ligand through the enzyme's six subsites.

Structure of the Aspergillus oryzae alpha-amylase complexed with the inhibitor acarbose at 2.0 A resolution.,Brzozowski AM, Davies GJ Biochemistry. 1997 Sep 9;36(36):10837-45. PMID:9283074<ref>PMID:9283074</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 7taa" style="background-color:#fffaf0;"></div>

==See Also==
*[[Amylase 3D structures|Amylase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Aspergillus oryzae]]
[[Category: Large Structures]]
[[Category: Brzozowski AM]]
[[Category: Davies GJ]]