View source for 1qi4


==MUTANT (E219G) MALTOTETRAOSE-FORMING EXO-AMYLASE IN COMPLEX WITH MALTOTETRAOSE==
<StructureSection load='1qi4' size='340' side='right'caption='[[1qi4]], [[Resolution|resolution]] 2.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1qi4]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Pseudomonas_stutzeri Pseudomonas stutzeri]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QI4 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1QI4 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]] 2&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=GLC:ALPHA-D-GLUCOSE'>GLC</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=1qi4 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1qi4 OCA], [https://pdbe.org/1qi4 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1qi4 RCSB], [https://www.ebi.ac.uk/pdbsum/1qi4 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1qi4 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/AMT4_STUST AMT4_STUST] 
== 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/qi/1qi4_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=1qi4 ConSurf].
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== Publication Abstract from PubMed ==
The crystal structures of the four product-complexed single mutants of the catalytic residues of Pseudomonas stutzeri maltotetraose-forming alpha-amylase, E219G, D193N, D193G and D294N, have been determined. Possible roles of the catalytic residues Glu219, Asp193 and Asp294 have been discussed by comparing the structures among the previously determined complexed mutant E219Q and the present mutant enzymes. The results suggested that Asp193 predominantly works as the base catalyst (nucleophile), whose side chain atom lies in close proximity to the C1-atom of Glc4, being involved in the intermediate formation in the hydrolysis reaction. While Asp294 works for tightly binding the substrate to give a twisted and a deformed conformation of the glucose ring at position -1 (Glc4). The hydrogen bond between the side chain atom of Glu219 and the O1-atom of Glc4, that implies the possibility of interaction via hydrogen, consistently present throughout these analyses, supports the generally accepted role of this residue as the acid catalyst (proton donor).

Roles of catalytic residues in alpha-amylases as evidenced by the structures of the product-complexed mutants of a maltotetraose-forming amylase.,Hasegawa K, Kubota M, Matsuura Y Protein Eng. 1999 Oct;12(10):819-24. PMID:10556241<ref>PMID:10556241</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 1qi4" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Pseudomonas stutzeri]]
[[Category: Hasegawa K]]
[[Category: Kubota M]]
[[Category: Matsuura Y]]