1d8c: Difference between revisions
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[[Image: | ==MALATE SYNTHASE G COMPLEXED WITH MAGNESIUM AND GLYOXYLATE== | ||
<StructureSection load='1d8c' size='340' side='right' caption='[[1d8c]], [[Resolution|resolution]] 2.00Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[1d8c]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1D8C OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1D8C FirstGlance]. <br> | |||
</td></tr><tr><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=GLV:GLYOXYLIC+ACID'>GLV</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene>, <scene name='pdbligand=SOR:D-SORBITOL'>SOR</scene><br> | |||
<tr><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=MSE:SELENOMETHIONINE'>MSE</scene></td></tr> | |||
<tr><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Malate_synthase Malate synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.3.3.9 2.3.3.9] </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=1d8c FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1d8c OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1d8c RCSB], [http://www.ebi.ac.uk/pdbsum/1d8c 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/d8/1d8c_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 == | |||
The crystal structure of selenomethionine-substituted malate synthase G, an 81 kDa monomeric enzyme from Escherichia coli has been determined by MAD phasing, model building, and crystallographic refinement to a resolution of 2.0 A. The crystallographic R factor is 0.177 for 49 242 reflections observed at the incident wavelength of 1.008 A, and the model stereochemistry is satisfactory. The basic fold of the enzyme is that of a beta8/alpha8 (TIM) barrel. The barrel is centrally located, with an N-terminal alpha-helical domain flanking one side. An inserted beta-sheet domain folds against the opposite side of the barrel, and an alpha-helical C-terminal domain forms a plug which caps the active site. Malate synthase catalyzes the condensation of glyoxylate and acetyl-coenzyme A and hydrolysis of the intermediate to yield malate and coenzyme A, requiring Mg(2+). The structure reveals an enzyme-substrate complex with glyoxylate and Mg(2+) which coordinates the aldehyde and carboxylate functions of the substrate. Two strictly conserved residues, Asp631 and Arg338, are proposed to provide concerted acid-base chemistry for the generation of the enol(ate) intermediate of acetyl-coenzyme A, while main-chain hydrogen bonds and bound Mg(2+) polarize glyoxylate in preparation for nucleophilic attack. The catalytic strategy of malate synthase appears to be essentially the same as that of citrate synthase, with the electrophile activated for nucleophilic attack by nearby positive charges and hydrogen bonds, while concerted acid-base catalysis accomplishes the abstraction of a proton from the methyl group of acetyl-coenzyme A. An active site aspartate is, however, the only common feature of these two enzymes, and the active sites of these enzymes are produced by quite different protein folds. Interesting similarities in the overall folds and modes of substrate recognition are discussed in comparisons of malate synthase with pyruvate kinase and pyruvate phosphate dikinase. | |||
Crystal structure of Escherichia coli malate synthase G complexed with magnesium and glyoxylate at 2.0 A resolution: mechanistic implications.,Howard BR, Endrizzi JA, Remington SJ Biochemistry. 2000 Mar 21;39(11):3156-68. PMID:10715138<ref>PMID:10715138</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
==See Also== | |||
*[[Malate synthase|Malate synthase]] | |||
== | == References == | ||
[[ | <references/> | ||
__TOC__ | |||
== | </StructureSection> | ||
< | |||
[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Malate synthase]] | [[Category: Malate synthase]] | ||
Revision as of 09:35, 4 September 2014
MALATE SYNTHASE G COMPLEXED WITH MAGNESIUM AND GLYOXYLATEMALATE SYNTHASE G COMPLEXED WITH MAGNESIUM AND GLYOXYLATE
Structural highlights
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 crystal structure of selenomethionine-substituted malate synthase G, an 81 kDa monomeric enzyme from Escherichia coli has been determined by MAD phasing, model building, and crystallographic refinement to a resolution of 2.0 A. The crystallographic R factor is 0.177 for 49 242 reflections observed at the incident wavelength of 1.008 A, and the model stereochemistry is satisfactory. The basic fold of the enzyme is that of a beta8/alpha8 (TIM) barrel. The barrel is centrally located, with an N-terminal alpha-helical domain flanking one side. An inserted beta-sheet domain folds against the opposite side of the barrel, and an alpha-helical C-terminal domain forms a plug which caps the active site. Malate synthase catalyzes the condensation of glyoxylate and acetyl-coenzyme A and hydrolysis of the intermediate to yield malate and coenzyme A, requiring Mg(2+). The structure reveals an enzyme-substrate complex with glyoxylate and Mg(2+) which coordinates the aldehyde and carboxylate functions of the substrate. Two strictly conserved residues, Asp631 and Arg338, are proposed to provide concerted acid-base chemistry for the generation of the enol(ate) intermediate of acetyl-coenzyme A, while main-chain hydrogen bonds and bound Mg(2+) polarize glyoxylate in preparation for nucleophilic attack. The catalytic strategy of malate synthase appears to be essentially the same as that of citrate synthase, with the electrophile activated for nucleophilic attack by nearby positive charges and hydrogen bonds, while concerted acid-base catalysis accomplishes the abstraction of a proton from the methyl group of acetyl-coenzyme A. An active site aspartate is, however, the only common feature of these two enzymes, and the active sites of these enzymes are produced by quite different protein folds. Interesting similarities in the overall folds and modes of substrate recognition are discussed in comparisons of malate synthase with pyruvate kinase and pyruvate phosphate dikinase. Crystal structure of Escherichia coli malate synthase G complexed with magnesium and glyoxylate at 2.0 A resolution: mechanistic implications.,Howard BR, Endrizzi JA, Remington SJ Biochemistry. 2000 Mar 21;39(11):3156-68. PMID:10715138[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences |
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