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[[Image: | ==Phosphate ions in D33S mutant fructose-1,6-bisphosphate aldolase from rabbit muscle== | ||
<StructureSection load='3dft' size='340' side='right' caption='[[3dft]], [[Resolution|resolution]] 1.94Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[3dft]] is a 4 chain structure with sequence from [http://en.wikipedia.org/wiki/Oryctolagus_cuniculus Oryctolagus cuniculus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3DFT OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3DFT FirstGlance]. <br> | |||
</td></tr><tr><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=PO4:PHOSPHATE+ION'>PO4</scene><br> | |||
<tr><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[3dfn|3dfn]], [[3dfo|3dfo]], [[3dfp|3dfp]], [[3dfq|3dfq]], [[3dfs|3dfs]]</td></tr> | |||
<tr><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">ALDOA ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9986 Oryctolagus cuniculus])</td></tr> | |||
<tr><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Fructose-bisphosphate_aldolase Fructose-bisphosphate aldolase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.1.2.13 4.1.2.13] </span></td></tr> | |||
<tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3dft FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3dft OCA], [http://www.rcsb.org/pdb/explore.do?structureId=3dft RCSB], [http://www.ebi.ac.uk/pdbsum/3dft PDBsum]</span></td></tr> | |||
<table> | |||
== 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/df/3dft_consurf.spt"</scriptWhenChecked> | |||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.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/chain_selection.php?pdb_ID=2ata ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Fructose-1,6-bisphosphate muscle aldolase is an essential glycolytic enzyme that catalyzes reversible carbon-carbon bond formation by cleaving fructose 1,6-bisphosphate to yield dihydroxyacetone phosphate (DHAP) and d-glyceraldehyde phosphate. To elucidate the mechanistic role of conserved amino acid Asp-33, Asn-33 and Ser-33 mutants were examined by kinetic and structural analyses. The mutations significantly compromised enzymatic activity and carbanion oxidation in presence of DHAP. Detailed structural analysis demonstrated that, like native crystals, Asp-33 mutant crystals, soaked in DHAP solutions, trapped Schiff base-derived intermediates covalently attached to Lys-229. The mutant structures, however, exhibited an abridged conformational change with the helical region (34-65) flanking the active site as well as pK(a) reductions and increased side chain disorder by central lysine residues, Lys-107 and Lys-146. These changes directly affect their interaction with the C-terminal Tyr-363, consistent with the absence of active site binding by the C-terminal region in the presence of phosphate. Lys-146 pK(a) reduction and side chain disorder would further compromise charge stabilization during C-C bond cleavage and proton transfer during enamine formation. These mechanistic impediments explain diminished catalytic activity and a reduced level of carbanion oxidation and are consistent with rate-determining proton transfer observed in the Asn-33 mutant. Asp-33 reduces the entropic cost and augments the enthalpic gain during catalysis by rigidifying Lys-107 and Lys-146, stabilizing their protonated forms, and promoting a conformational change triggered by substrate or obligate product binding, which lower kinetic barriers in C-C bond cleavage and Schiff base-enamine interconversion. | |||
Charge Stabilization and Entropy Reduction of Central Lysine Residues in Fructose-Bisphosphate Aldolase.,St-Jean M, Blonski C, Sygusch J Biochemistry. 2009 Apr 22. PMID:19354220<ref>PMID:19354220</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
==See Also== | ==See Also== | ||
*[[Aldolase|Aldolase]] | *[[Aldolase|Aldolase]] | ||
== References == | |||
== | <references/> | ||
< | __TOC__ | ||
</StructureSection> | |||
[[Category: Fructose-bisphosphate aldolase]] | [[Category: Fructose-bisphosphate aldolase]] | ||
[[Category: Oryctolagus cuniculus]] | [[Category: Oryctolagus cuniculus]] |