View source for 4hhm


==Crystal structure of a mutant, G219A, of Glucose Isomerase from Streptomyces sp. SK==
<StructureSection load='4hhm' size='340' side='right'caption='[[4hhm]], [[Resolution|resolution]] 2.15&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4hhm]] is a 8 chain structure with sequence from [https://en.wikipedia.org/wiki/Streptomyces_sp._SK Streptomyces sp. SK]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4HHM OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4HHM 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]] 2.15&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CO:COBALT+(II)+ION'>CO</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</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=4hhm FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4hhm OCA], [https://pdbe.org/4hhm PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4hhm RCSB], [https://www.ebi.ac.uk/pdbsum/4hhm PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4hhm ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q9ZAI3_9ACTN Q9ZAI3_9ACTN] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The role of residue 219 in the physicochemical properties of D-glucose isomerase from Streptomyces sp. SK strain (SKGI) was investigated by site-directed mutagenesis and structural studies. Mutants G219A, G219N, and G219F were generated and characterized. Comparative studies of their physicochemical properties with those of the wild-type enzyme highlighted that mutant G219A displayed increased specific activity and thermal stability compared to that of the wild-type enzyme, while for G219N and G219F, these properties were considerably decreased. A double mutant, SKGI F53L/G219A, displayed a higher optimal temperature and a higher catalytic efficiency than both the G219A mutant and the wild-type enzyme and showed a half-life time of about 150 min at 85 degrees C as compared to 50 min for wild-type SKGI. Crystal structures of SKGI wild-type and G219A enzymes were solved to 1.73 and 2.15 A, respectively, and showed that the polypeptide chain folds into two structural domains. The larger domain consists of a (beta/alpha)8 unit, and the smaller domain forms a loop of alpha helices. Detailed analyses of the three-dimensional structures highlighted minor but important changes in the active site region as compared to that of the wild-type enzyme leading to a displacement of both metal ions, and in particular that in site M2. The structural analyses moreover revealed how the substitution of G219 by an alanine plays a crucial role in improving the thermostability of the mutant enzyme.

Identification of critical residues for the activity and thermostability of Streptomyces sp. SK glucose isomerase.,Ben Hlima H, Bejar S, Riguet J, Haser R, Aghajari N Appl Microbiol Biotechnol. 2013 Mar 6. PMID:23463249<ref>PMID:23463249</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4hhm" style="background-color:#fffaf0;"></div>

==See Also==
*[[D-xylose isomerase 3D structures|D-xylose isomerase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Streptomyces sp. SK]]
[[Category: Aghajari N]]
[[Category: Ben Hlima H]]
[[Category: Haser R]]
[[Category: Riguet J]]