View source for 3dk8

==Catalytic cycle of human glutathione reductase near 1 A resolution==
<StructureSection load='3dk8' size='340' side='right' caption='[[3dk8]], [[Resolution|resolution]] 1.10&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3dk8]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3DK8 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3DK8 FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=FAD:FLAVIN-ADENINE+DINUCLEOTIDE'>FAD</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=GSH:GLUTATHIONE'>GSH</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr>
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[3djg|3djg]], [[3djj|3djj]], [[3dk4|3dk4]], [[3dk9|3dk9]]</td></tr>
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">GSR, GLUR, GRD1 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 HUMAN])</td></tr>
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Glutathione-disulfide_reductase Glutathione-disulfide reductase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.8.1.7 1.8.1.7] </span></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3dk8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3dk8 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=3dk8 RCSB], [http://www.ebi.ac.uk/pdbsum/3dk8 PDBsum]</span></td></tr>
</table>
== 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/dk/3dk8_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.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/chain_selection.php?pdb_ID=2ata ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Efficient enzyme catalysis depends on exquisite details of structure beyond those resolvable in typical medium- and high-resolution crystallographic analyses. Here we report synchrotron-based cryocrystallographic studies of natural substrate complexes of the flavoenzyme human glutathione reductase (GR) at nominal resolutions between 1.1 and 0.95 A that reveal new aspects of its mechanism. Compression in the active site causes overlapping van der Waals radii and distortion in the nicotinamide ring of the NADPH substrate, which enhances catalysis via stereoelectronic effects. The bound NADPH and redox-active disulfide are positioned optimally on opposite sides of the flavin for a 1,2-addition across a flavin double bond. The new structures extend earlier observations to reveal that the redox-active disulfide loop in GR is an extreme case of sequential peptide bonds systematically deviating from planarity--a net deviation of 53 degrees across five residues. But this apparent strain is not a factor in catalysis, as it is present in both oxidized and reduced structures. Intriguingly, the flavin bond lengths in oxidized GR are intermediate between those expected for oxidized and reduced flavin, but we present evidence that this may not be due to the protein environment but instead due to partial synchrotron reduction of the flavin by the synchrotron beam. Finally, of more general relevance, we present evidence that the structures of synchrotron-reduced disulfide bonds cannot generally be used as reliable models for naturally reduced disulfide bonds.

Catalytic cycle of human glutathione reductase near 1 A resolution.,Berkholz DS, Faber HR, Savvides SN, Karplus PA J Mol Biol. 2008 Oct 3;382(2):371-84. Epub 2008 Jul 7. PMID:18638483<ref>PMID:18638483</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Glutathione Reductase|Glutathione Reductase]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Glutathione-disulfide reductase]]
[[Category: Human]]
[[Category: Berkholz, D S]]
[[Category: Faber, H R]]
[[Category: Karplus, P A]]
[[Category: Savvides, S N]]
[[Category: Alternative initiation]]
[[Category: Fad]]
[[Category: Flavoenzyme]]
[[Category: Flavoprotein]]
[[Category: Glutathione]]
[[Category: Mitochondrion]]
[[Category: Nadp]]
[[Category: Nicotinamide]]
[[Category: Oxidoreductase]]
[[Category: Phosphoprotein]]
[[Category: Redox-active center]]
[[Category: Transit peptide]]