1cmt: Difference between revisions
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==THE ROLE OF ASPARTATE-235 IN THE BINDING OF CATIONS TO AN ARTIFICIAL CAVITY AT THE RADICAL SITE OF CYTOCHROME C PEROXIDASE== | ==THE ROLE OF ASPARTATE-235 IN THE BINDING OF CATIONS TO AN ARTIFICIAL CAVITY AT THE RADICAL SITE OF CYTOCHROME C PEROXIDASE== | ||
<StructureSection load='1cmt' size='340' side='right' caption='[[1cmt]], [[Resolution|resolution]] 2.10Å' scene=''> | <StructureSection load='1cmt' size='340' side='right'caption='[[1cmt]], [[Resolution|resolution]] 2.10Å' scene=''> | ||
== Structural highlights == | == Structural highlights == | ||
<table><tr><td colspan='2'>[[1cmt]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Atcc_18824 Atcc 18824]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1CMT OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1CMT FirstGlance]. <br> | <table><tr><td colspan='2'>[[1cmt]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Atcc_18824 Atcc 18824]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1CMT OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1CMT FirstGlance]. <br> | ||
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Check<jmol> | Check<jmol> | ||
<jmolCheckbox> | <jmolCheckbox> | ||
<scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/cm/1cmt_consurf.spt"</scriptWhenChecked> | <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/cm/1cmt_consurf.spt"</scriptWhenChecked> | ||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | ||
<text>to colour the structure by Evolutionary Conservation</text> | <text>to colour the structure by Evolutionary Conservation</text> | ||
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</div> | </div> | ||
<div class="pdbe-citations 1cmt" style="background-color:#fffaf0;"></div> | <div class="pdbe-citations 1cmt" style="background-color:#fffaf0;"></div> | ||
==See Also== | |||
*[[Cytochrome c peroxidase 3D structures|Cytochrome c peroxidase 3D structures]] | |||
== References == | == References == | ||
<references/> | <references/> | ||
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[[Category: Atcc 18824]] | [[Category: Atcc 18824]] | ||
[[Category: Cytochrome-c peroxidase]] | [[Category: Cytochrome-c peroxidase]] | ||
[[Category: Large Structures]] | |||
[[Category: Fitzgerald, M M]] | [[Category: Fitzgerald, M M]] | ||
[[Category: Goodin, D B]] | [[Category: Goodin, D B]] | ||
Revision as of 10:17, 10 October 2019
THE ROLE OF ASPARTATE-235 IN THE BINDING OF CATIONS TO AN ARTIFICIAL CAVITY AT THE RADICAL SITE OF CYTOCHROME C PEROXIDASETHE ROLE OF ASPARTATE-235 IN THE BINDING OF CATIONS TO AN ARTIFICIAL CAVITY AT THE RADICAL SITE OF CYTOCHROME C PEROXIDASE
Structural highlights
Function[CCPR_YEAST] Destroys radicals which are normally produced within the cells and which are toxic to biological systems. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe activated state of cytochrome c peroxidase, compound ES, contains a cation radical on the Trp-191 side chain. We recently reported that replacing this tryptophan with glycine creates a buried cavity at the active site that contains ordered solvent and that will specifically bind substituted imidazoles in their protonated cationic forms (Fitzgerald MM, Churchill MJ, McRee DE, Goodin DB, 1994, Biochemistry 33:3807-3818). Proposals that a nearby carboxylate, Asp-235, and competing monovalent cations should modulate the affinity of the W191G cavity for ligand binding are addressed in this study. Competitive binding titrations of the imidazolium ion to W191G as a function of [K+] show that potassium competes weakly with the binding of imidazoles. The dissociation constant observed for potassium binding (18 mM) is more than 3,000-fold higher than that for 1,2-dimethylimidazole (5.5 microM) in the absence of competing cations. Significantly, the W191G-D235N double mutant shows no evidence for binding imidazoles in their cationic or neutral forms, even though the structure of the cavity remains largely unperturbed by replacement of the carboxylate. Refined crystallographic B-values of solvent positions indicate that the weakly bound potassium in W191G is significantly depopulated in the double mutant. These results demonstrate that the buried negative charge of Asp-235 is an essential feature of the cation binding determinant and indicate that this carboxylate plays a critical role in stabilizing the formation of the Trp-191 radical cation. The role of aspartate-235 in the binding of cations to an artificial cavity at the radical site of cytochrome c peroxidase.,Fitzgerald MM, Trester ML, Jensen GM, McRee DE, Goodin DB Protein Sci. 1995 Sep;4(9):1844-50. PMID:8528082[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences |
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