1ami: Difference between revisions
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==STERIC AND CONFORMATIONAL FEATURES OF THE ACONITASE MECHANISM== | ==STERIC AND CONFORMATIONAL FEATURES OF THE ACONITASE MECHANISM== | ||
<StructureSection load='1ami' size='340' side='right' caption='[[1ami]], [[Resolution|resolution]] 2.00Å' scene=''> | <StructureSection load='1ami' size='340' side='right'caption='[[1ami]], [[Resolution|resolution]] 2.00Å' scene=''> | ||
== Structural highlights == | == Structural highlights == | ||
<table><tr><td colspan='2'>[[1ami]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Bovin Bovin]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1AMI OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1AMI FirstGlance]. <br> | <table><tr><td colspan='2'>[[1ami]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Bovin Bovin]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1AMI OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1AMI 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/am/1ami_consurf.spt"</scriptWhenChecked> | <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/am/1ami_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 1ami" style="background-color:#fffaf0;"></div> | <div class="pdbe-citations 1ami" style="background-color:#fffaf0;"></div> | ||
==See Also== | |||
*[[Aconitase 3D structures|Aconitase 3D structures]] | |||
== References == | == References == | ||
<references/> | <references/> | ||
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[[Category: Aconitate hydratase]] | [[Category: Aconitate hydratase]] | ||
[[Category: Bovin]] | [[Category: Bovin]] | ||
[[Category: Large Structures]] | |||
[[Category: Stout, C D]] | [[Category: Stout, C D]] | ||
Revision as of 10:23, 10 October 2019
STERIC AND CONFORMATIONAL FEATURES OF THE ACONITASE MECHANISMSTERIC AND CONFORMATIONAL FEATURES OF THE ACONITASE MECHANISM
Structural highlights
Function[ACON_BOVIN] Catalyzes the isomerization of citrate to isocitrate via cis-aconitate. 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 PubMedCrystal structures of mitochondrial aconitase with alpha-methylisocitrate and with sulfate bound have been solved and refined at 2.0 A resolution with R factors of 18.2 and 16.8%, respectively. The steric factors and conformational effects observed in both new structures support the proposed mechanism for the overall reaction catalyzed by aconitase. The alternate substrate alpha-methylisocitrate is derived from alpha-methyl-cis-aconitate during crystallization and is observed to bind in the active site in a manner very similar to that observed for isocitrate. The methyl group is accommodated by favorable contact with Ile-425. However, the other potential hydration product of alpha-methyl-cis-aconitate, alpha-methylcitrate, cannot be accommodated in the active site due to steric conflict of the methyl group with Asp-165. The results are consistent with the requirement that cis-aconitate must bind in two ways, in the citrate mode and in the isocitrate mode. Crystals of aconitase with sulfate bound are isomorphous to those with isocitrate bound. However, the structure displays significant conformational changes, providing a model for the substrate-free state of enzyme. Three water molecules bind in place of the C alpha- and C beta-hydroxyl and carboxyl groups of isocitrate, while sulfate binds in place of the C gamma-carboxyl group. Side chains of Ser-642 and Arg-447 in the active site rotate to pair with other side chains in the absence of substrate. The new conformation of Arg-447 triggers a concerted set of shifts which transmits conformational change to the surface of the protein, 30 A from the active site. In the absence of substrate, a chain segment containing the [4Fe-4S] ligand Cys-358 also shifts, resulting in the net translation and reorientation of the Fe-S cluster. Steric and conformational features of the aconitase mechanism.,Lauble H, Stout CD Proteins. 1995 May;22(1):1-11. PMID:7675781[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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