2x07: Difference between revisions
New page: '''Unreleased structure''' The entry 2x07 is ON HOLD Authors: Murphy, E.J., Metcalfe, C.L., Gumiero, A., Raven, E.L., Moody, P.C.E. Description: cytochrome c peroxidase: engineered asc... |
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The | ==cytochrome c peroxidase: engineered ascorbate binding site== | ||
<StructureSection load='2x07' size='340' side='right'caption='[[2x07]], [[Resolution|resolution]] 1.86Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[2x07]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2X07 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2X07 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]] 1.86Å</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=2x07 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2x07 OCA], [https://pdbe.org/2x07 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2x07 RCSB], [https://www.ebi.ac.uk/pdbsum/2x07 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2x07 ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/CCPR_YEAST CCPR_YEAST] Destroys radicals which are normally produced within the cells and which are toxic to biological systems. | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
The binding of substrates to heme enzymes has been widely assumed to occur at the so-called delta-heme edge. Recently, however, a number of examples have appeared in which substrate binding at an alternative site, the gamma-heme edge, is also possible. In previous work [Sharp et al. (2003) Nat. Struct. Biol. 10, 303-307], we showed that binding of ascorbate to ascorbate peroxidase occurred at the gamma-heme edge. Here, we show that the closely related cytochrome c peroxidase enzyme can duplicate the substrate binding properties of ascorbate peroxidase through the introduction of relatively modest structural changes at Tyr36 and Asn184. Hence, crystallographic data for the Y36A/N184R/W191F triple variant of cytochrome c peroxidase shows ascorbate bound to the gamma-heme edge, with hydrogen bonds to the heme propionate and Arg184. In parallel mechanistic studies in variants incorporating the W191F mutation, we show that a transient porphyrin pi-cation radical in Compound I of cytochrome c peroxidase, analogous to that observed in ascorbate peroxidase, is competent for ascorbate oxidation but that under steady state conditions this intermediate decays too rapidly to sustain efficient turnover of ascorbate. The results are discussed in terms of our more general understanding of substrate oxidation across other heme proteins, and the emerging role of the heme propionates at the gamma-heme edge. | |||
Engineering the substrate specificity and reactivity of a heme protein: creation of an ascorbate binding site in cytochrome c peroxidase.,Murphy EJ, Metcalfe CL, Basran J, Moody PC, Raven EL Biochemistry. 2008 Dec 30;47(52):13933-41. PMID:19061385<ref>PMID:19061385</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 2x07" style="background-color:#fffaf0;"></div> | |||
==See Also== | |||
*[[Cytochrome c peroxidase 3D structures|Cytochrome c peroxidase 3D structures]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Large Structures]] | |||
[[Category: Saccharomyces cerevisiae]] | |||
[[Category: Gumiero A]] | |||
[[Category: Metcalfe CL]] | |||
[[Category: Moody PCE]] | |||
[[Category: Murphy EJ]] | |||
[[Category: Raven EL]] | |||
Latest revision as of 13:20, 20 December 2023
cytochrome c peroxidase: engineered ascorbate binding sitecytochrome c peroxidase: engineered ascorbate binding site
Structural highlights
FunctionCCPR_YEAST Destroys radicals which are normally produced within the cells and which are toxic to biological systems. Publication Abstract from PubMedThe binding of substrates to heme enzymes has been widely assumed to occur at the so-called delta-heme edge. Recently, however, a number of examples have appeared in which substrate binding at an alternative site, the gamma-heme edge, is also possible. In previous work [Sharp et al. (2003) Nat. Struct. Biol. 10, 303-307], we showed that binding of ascorbate to ascorbate peroxidase occurred at the gamma-heme edge. Here, we show that the closely related cytochrome c peroxidase enzyme can duplicate the substrate binding properties of ascorbate peroxidase through the introduction of relatively modest structural changes at Tyr36 and Asn184. Hence, crystallographic data for the Y36A/N184R/W191F triple variant of cytochrome c peroxidase shows ascorbate bound to the gamma-heme edge, with hydrogen bonds to the heme propionate and Arg184. In parallel mechanistic studies in variants incorporating the W191F mutation, we show that a transient porphyrin pi-cation radical in Compound I of cytochrome c peroxidase, analogous to that observed in ascorbate peroxidase, is competent for ascorbate oxidation but that under steady state conditions this intermediate decays too rapidly to sustain efficient turnover of ascorbate. The results are discussed in terms of our more general understanding of substrate oxidation across other heme proteins, and the emerging role of the heme propionates at the gamma-heme edge. Engineering the substrate specificity and reactivity of a heme protein: creation of an ascorbate binding site in cytochrome c peroxidase.,Murphy EJ, Metcalfe CL, Basran J, Moody PC, Raven EL Biochemistry. 2008 Dec 30;47(52):13933-41. PMID:19061385[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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