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| - | [[Image:1p48.gif|left|200px]] | |
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| - | {{Structure
| + | ==REVERSE PROTONATION IS THE KEY TO GENERAL ACID-BASE CATALYSIS IN ENOLASE== |
| - | |PDB= 1p48 |SIZE=350|CAPTION= <scene name='initialview01'>1p48</scene>, resolution 2.00Å
| + | <StructureSection load='1p48' size='340' side='right'caption='[[1p48]], [[Resolution|resolution]] 2.00Å' scene=''> |
| - | |SITE=
| + | == Structural highlights == |
| - | |LIGAND= <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=PEP:PHOSPHOENOLPYRUVATE'>PEP</scene>
| + | <table><tr><td colspan='2'>[[1p48]] is a 2 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=1P48 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1P48 FirstGlance]. <br> |
| - | |ACTIVITY= <span class='plainlinks'>[http://en.wikipedia.org/wiki/Phosphopyruvate_hydratase Phosphopyruvate hydratase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.2.1.11 4.2.1.11] </span>
| + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2Å</td></tr> |
| - | |GENE= ENO1 OR ENOA OR HSP48 OR YGR254W OR G9160 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=4932 Saccharomyces cerevisiae])
| + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=PEP:PHOSPHOENOLPYRUVATE'>PEP</scene></td></tr> |
| - | |DOMAIN=
| + | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1p48 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1p48 OCA], [https://pdbe.org/1p48 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1p48 RCSB], [https://www.ebi.ac.uk/pdbsum/1p48 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1p48 ProSAT]</span></td></tr> |
| - | |RELATEDENTRY=[[1p43|1P43]]
| + | </table> |
| - | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1p48 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1p48 OCA], [http://www.ebi.ac.uk/pdbsum/1p48 PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1p48 RCSB]</span>
| + | == Function == |
| - | }}
| + | [https://www.uniprot.org/uniprot/ENO1_YEAST ENO1_YEAST] |
| | + | == 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/p4/1p48_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/main_output.php?pdb_ID=1p48 ConSurf]. |
| | + | <div style="clear:both"></div> |
| | | | |
| - | '''REVERSE PROTONATION IS THE KEY TO GENERAL ACID-BASE CATALYSIS IN ENOLASE'''
| + | ==See Also== |
| - | | + | *[[Enolase 3D structures|Enolase 3D structures]] |
| - | | + | __TOC__ |
| - | ==Overview== | + | </StructureSection> |
| - | The pH dependence of enolase catalysis was studied to understand how enolase is able to utilize both general acid and general base catalysis in each direction of the reaction at near-neutral pHs. Wild-type enolase from yeast was assayed in the dehydration reaction (2-phospho-D-glycerate --> phosphoenolpyruvate + H(2)O) at different pHs. E211Q, a site-specific variant of enolase that catalyzes the exchange of the alpha-proton of 2-phospho-D-glycerate but not the complete dehydration, was assayed in a (1)H/(2)H exchange reaction at different pDs. Additionally, crystal structures of E211Q and E168Q were obtained at 2.0 and 1.8 A resolution, respectively. Analysis of the pH profile of k(cat)/K(Mg) for wild-type enolase yielded macroscopic pK(a) estimates of 7.4 +/- 0.3 and 9.0 +/- 0.3, while the results of the pD profile of the exchange reaction of E211Q led to a pK(a) estimate of 9.5 +/- 0.1. These values permit estimates of the four microscopic pK(a)s that describe the four relevant protonation states of the acid/base catalytic groups in the active site. The analysis indicates that the dehydration reaction is catalyzed by a small fraction of enzyme that is reverse-protonated (i.e., Lys345-NH(2), Glu211-COOH), whereas the hydration reaction is catalyzed by a larger fraction of the enzyme that is typically protonated (i.e., Lys345-NH(3)(+), Glu211-COO(-)). These two forms of the enzyme coexist in a constant, pH-independent ratio. The structures of E211Q and E168Q both show virtually identical folds and active-site architectures (as compared to wild-type enolase) and thus provide additional support to the conclusions reported herein. Other enzymes that require both general acid and general base catalysis likely require reverse protonation of catalytic groups in one direction of the reaction.
| + | [[Category: Large Structures]] |
| - | | + | |
| - | ==About this Structure==
| + | |
| - | 1P48 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1P48 OCA].
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| - | | + | |
| - | ==Reference==
| + | |
| - | Reverse protonation is the key to general acid-base catalysis in enolase., Sims PA, Larsen TM, Poyner RR, Cleland WW, Reed GH, Biochemistry. 2003 Jul 15;42(27):8298-306. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/12846578 12846578]
| + | |
| - | [[Category: Phosphopyruvate hydratase]] | + | |
| | [[Category: Saccharomyces cerevisiae]] | | [[Category: Saccharomyces cerevisiae]] |
| - | [[Category: Single protein]]
| + | [[Category: Cleland WW]] |
| - | [[Category: Cleland, W W.]] | + | [[Category: Larsen TM]] |
| - | [[Category: Larsen, T M.]] | + | [[Category: Poyner RR]] |
| - | [[Category: Poyner, R R.]] | + | [[Category: Reed GH]] |
| - | [[Category: Reed, G H.]] | + | [[Category: Sims PA]] |
| - | [[Category: Sims, P A.]] | + | |
| - | [[Category: beta barrel]]
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| - | | + | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 22:54:33 2008''
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