View source for 1gq1


==CYTOCHROME CD1 NITRITE REDUCTASE, Y25S mutant, OXIDISED FORM==
<StructureSection load='1gq1' size='340' side='right'caption='[[1gq1]], [[Resolution|resolution]] 1.40&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1gq1]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Atcc_35512 Atcc 35512]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1GQ1 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1GQ1 FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=DHE:HEME+D'>DHE</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=HEC:HEME+C'>HEC</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"><div style='overflow: auto; max-height: 3em;'>[[1h9x|1h9x]], [[1h9y|1h9y]], [[1hcm|1hcm]], [[1hj3|1hj3]], [[1hj4|1hj4]], [[1hj5|1hj5]]</div></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=1gq1 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1gq1 OCA], [https://pdbe.org/1gq1 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1gq1 RCSB], [https://www.ebi.ac.uk/pdbsum/1gq1 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1gq1 ProSAT]</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/gq/1gq1_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/main_output.php?pdb_ID=1gq1 ConSurf].
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== Publication Abstract from PubMed ==
The 1.4-A crystal structure of the oxidized state of a Y25S variant of cytochrome cd(1) nitrite reductase from Paracoccus pantotrophus is described. It shows that loss of Tyr(25), a ligand via its hydroxy group to the iron of the d(1) heme in the oxidized (as prepared) wild-type enzyme, does not result in a switch at the c heme of the unusual bishistidinyl coordination to the histidine/methionine coordination seen in other conformations of the enzyme. The Ser(25) side chain is seen in two positions in the d(1) heme pocket with relative occupancies of approximately 7:3, but in neither case is the hydroxy group bound to the iron atom; instead, a sulfate ion from the crystallization solution is bound between the Ser(25) side chain and the heme iron. Unlike the wild-type enzyme, the Y25S mutant is active as a reductase toward nitrite, oxygen, and hydroxylamine without a reductive activation step. It is concluded that Tyr(25) is not essential for catalysis of reduction of any substrate, but that the requirement for activation by reduction of the wild-type enzyme is related to a requirement to drive the dissociation of this residue from the active site. The Y25S protein retains the d(1) heme less well than the wild-type protein, suggesting that the tyrosine residue has a role in stabilizing the binding of this cofactor.

Structure and kinetic properties of Paracoccus pantotrophus cytochrome cd1 nitrite reductase with the d1 heme active site ligand tyrosine 25 replaced by serine.,Gordon EH, Sjogren T, Lofqvist M, Richter CD, Allen JW, Higham CW, Hajdu J, Fulop V, Ferguson SJ J Biol Chem. 2003 Apr 4;278(14):11773-81. Epub 2003 Jan 28. PMID:12556530<ref>PMID:12556530</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 1gq1" style="background-color:#fffaf0;"></div>

==See Also==
*[[Cytochrome C 3D structures|Cytochrome C 3D structures]]
*[[Nitrite reductase 3D structures|Nitrite reductase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Atcc 35512]]
[[Category: Large Structures]]
[[Category: Ferguson, S J]]
[[Category: Gordon, E H.J]]
[[Category: Hajdu, J]]
[[Category: Lofqvist, M]]
[[Category: Richter, C D]]
[[Category: Sjogren, T]]
[[Category: Denitrification]]
[[Category: Electron transport]]
[[Category: Enzyme]]
[[Category: Nitrite reductase]]
[[Category: Oxidoreductase]]
[[Category: Periplasmic]]
[[Category: Reductase]]