4b5k: Difference between revisions
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<StructureSection load='4b5k' size='340' side='right'caption='[[4b5k]], [[Resolution|resolution]] 1.70Å' scene=''> | <StructureSection load='4b5k' size='340' side='right'caption='[[4b5k]], [[Resolution|resolution]] 1.70Å' scene=''> | ||
== Structural highlights == | == Structural highlights == | ||
<table><tr><td colspan='2'>[[4b5k]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/ | <table><tr><td colspan='2'>[[4b5k]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Mycothermus_thermophilus Mycothermus thermophilus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4B5K OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4B5K FirstGlance]. <br> | ||
</td></tr><tr id=' | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.7Å</td></tr> | ||
<tr id=' | <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=HDD:CIS-HEME+D+HYDROXYCHLORIN+GAMMA-SPIROLACTONE'>HDD</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=4b5k FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4b5k OCA], [https://pdbe.org/4b5k PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4b5k RCSB], [https://www.ebi.ac.uk/pdbsum/4b5k PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4b5k ProSAT]</span></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=4b5k FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4b5k OCA], [https://pdbe.org/4b5k PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4b5k RCSB], [https://www.ebi.ac.uk/pdbsum/4b5k PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4b5k ProSAT]</span></td></tr> | ||
</table> | </table> | ||
== Function == | |||
[https://www.uniprot.org/uniprot/R4GRT9_9PEZI R4GRT9_9PEZI] Occurs in almost all aerobically respiring organisms and serves to protect cells from the toxic effects of hydrogen peroxide.[RuleBase:RU004142] Serves to protect cells from the toxic effects of hydrogen peroxide.[PIRNR:PIRNR038927] | |||
<div style="background-color:#fffaf0;"> | <div style="background-color:#fffaf0;"> | ||
== Publication Abstract from PubMed == | == Publication Abstract from PubMed == | ||
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__TOC__ | __TOC__ | ||
</StructureSection> | </StructureSection> | ||
[[Category: Large Structures]] | [[Category: Large Structures]] | ||
[[Category: | [[Category: Mycothermus thermophilus]] | ||
[[Category: | [[Category: McPherson MJ]] | ||
[[Category: | [[Category: Ogel ZB]] | ||
[[Category: | [[Category: Pearson AR]] | ||
[[Category: | [[Category: Trinh CH]] | ||
[[Category: | [[Category: Yuzugullu Y]] | ||
Latest revision as of 13:57, 9 May 2024
Probing the active center of catalase-phenol oxidase from Scytalidium thermophilumProbing the active center of catalase-phenol oxidase from Scytalidium thermophilum
Structural highlights
FunctionR4GRT9_9PEZI Occurs in almost all aerobically respiring organisms and serves to protect cells from the toxic effects of hydrogen peroxide.[RuleBase:RU004142] Serves to protect cells from the toxic effects of hydrogen peroxide.[PIRNR:PIRNR038927] Publication Abstract from PubMedAlmost all monofunctional haem catalases contain a highly conserved core containing the active site, which is connected to the exterior of the enzyme by three channels. These channels have been identified as potential routes for substrate flow and product release. To further investigate the role of these molecular channels, a series of mutants of Scytalidium thermophilum catalase were generated. The three-dimensional structures of four catalase variants, N155A, V123A, V123C and V123T, have been determined at resolutions of 2.25, 1.93, 1.9 and 1.7 A, respectively. The V123C variant contains a new covalent bond between the S atom of Cys123 and the imidazole ring of the essential His82. This variant enzyme has only residual catalase activity and contains haem b instead of the normal haem d. The H82A variant demonstrates low catalase and phenol oxidase activities (0.2 and 20% of those of recombinant wild-type catalase-phenol oxidase, respectively). The N155A and N155H variants exhibit 4.5 and 3% of the wild-type catalase activity and contain haem d, showing that Asn155 is essential for catalysis but is not required for the conversion of haem b to haem d. Structural analysis suggests that the cause of the effect of these mutations on catalysis is the disruption of the ability of dioxygen substrates to efficiently access the active site. Additional mutants have been characterized biochemically to further probe the roles of the different channels. Introducing smaller or polar side chains in place of Val123 reduces the catalase activity. The F160V, F161V and F168V mutants show a marked decrease in catalase activity but have a much lower effect on the phenol oxidase activity, despite containing substoichiometric amounts of haem. Investigating the active centre of the Scytalidium thermophilum catalase.,Yuzugullu Y, Trinh CH, Fairhurst L, Ogel ZB, McPherson MJ, Pearson AR Acta Crystallogr Sect F Struct Biol Cryst Commun. 2013 Apr 1;69(Pt 4):369-75., doi: 10.1107/S1744309113004211. Epub 2013 Mar 28. PMID:23545640[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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