View source for 1qf7


==STRUCTURE OF THE MUTANT HIS392GLN OF CATALASE HPII FROM E. COLI==
<StructureSection load='1qf7' size='340' side='right'caption='[[1qf7]], [[Resolution|resolution]] 2.20&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1qf7]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QF7 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1QF7 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]] 2.2&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</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=1qf7 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1qf7 OCA], [https://pdbe.org/1qf7 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1qf7 RCSB], [https://www.ebi.ac.uk/pdbsum/1qf7 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1qf7 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/CATE_ECOLI CATE_ECOLI] Decomposes hydrogen peroxide into water and oxygen; serves to protect cells from the toxic effects of hydrogen peroxide.
== 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/qf/1qf7_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=1qf7 ConSurf].
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== Publication Abstract from PubMed ==
The three-dimensional structures of two HPII variants, V169C and H392Q, have been determined at resolutions of 1.8 and 2.1 A, respectively. The V169C variant contains a new type of covalent bond between the sulfur atom of Cys(169) and a carbon atom on the imidazole ring of the essential His(128). This variant enzyme has only residual catalytic activity and contains heme b. The chain of water molecules visible in the main channel may reflect the organization of the hydrogen peroxide substrates in the active enzyme. Two alternative mechanisms, involving either compound I or free radical intermediates, are presented to explain the formation of the Cys-His covalent bond. The H392Q and H392E variants exhibit 75 and 25% of native catalytic activity, respectively. The Gln(392) variant contains only heme b, whereas the Glu(392) variant contains a mixture of heme b and cis and trans isomers of heme d, suggesting of a role for this residue in heme conversion. Replacement of either Gln(419) and Ser(414), both of which interact with the heme, affected the cis:trans ratio of spirolactone heme d. Implications for the heme oxidation mechanism and the His-Tyr bond formation in HPII are considered.

Mutants that alter the covalent structure of catalase hydroperoxidase II from Escherichia coli.,Mate MJ, Sevinc MS, Hu B, Bujons J, Bravo J, Switala J, Ens W, Loewen PC, Fita I J Biol Chem. 1999 Sep 24;274(39):27717-25. PMID:10488114<ref>PMID:10488114</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 1qf7" style="background-color:#fffaf0;"></div>

==See Also==
*[[Catalase 3D structures|Catalase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli]]
[[Category: Large Structures]]
[[Category: Fita I]]
[[Category: Loewen PC]]
[[Category: Mate MJ]]