3qn6
From Proteopedia
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| - | [[ | + | ==Crystal Structures of Escherichia coli Aspartate Aminotransferase Reconstituted with 1-Deaza-Pyridoxal 5'-Phosphate: Internal Aldimine and Stable L-Aspartate External Aldimine== |
| + | <StructureSection load='3qn6' size='340' side='right' caption='[[3qn6]], [[Resolution|resolution]] 1.79Å' scene=''> | ||
| + | == Structural highlights == | ||
| + | <table><tr><td colspan='2'>[[3qn6]] 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=3QN6 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3QN6 FirstGlance]. <br> | ||
| + | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr> | ||
| + | <tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=3QN:(E)-N~6~-{2-HYDROXY-3-METHYL-6-[(PHOSPHONOOXY)METHYL]BENZYLIDENE}-L-LYSINE'>3QN</scene></td></tr> | ||
| + | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">aspC, b0928, JW0911 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 Escherichia coli])</td></tr> | ||
| + | <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Aspartate_transaminase Aspartate transaminase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.6.1.1 2.6.1.1] </span></td></tr> | ||
| + | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3qn6 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3qn6 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=3qn6 RCSB], [http://www.ebi.ac.uk/pdbsum/3qn6 PDBsum]</span></td></tr> | ||
| + | </table> | ||
| + | <div style="background-color:#fffaf0;"> | ||
| + | == Publication Abstract from PubMed == | ||
| + | The 1.8 A resolution crystal structures of Escherichia coli aspartate aminotransferase reconstituted with 1-deazapyridoxal 5'-phosphate (deazaPLP; 2-formyl-3-hydroxy-4-methylbenzyl phosphate) in the internal aldimine and l-aspartate external aldimine forms are reported. The l-aspartate.deazaPLP external aldimine is extraordinarily stable (half-life of >20 days), allowing crystals of this intermediate to be grown by cocrystallization with l-aspartate. This structure is compared to that of the alpha-methyl-l-aspartate.PLP external aldimine. Overlays with the corresponding pyridoxal 5'-phosphate (PLP) aldimines show very similar orientations of deazaPLP with respect to PLP. The lack of a hydrogen bond between Asp222 and deazaPLP, which serves to "anchor" PLP in the active site, releases strain in the deazaPLP internal aldimine that is enforced in the PLP internal aldimine [Hayashi, H., Mizuguchi, H., Miyahara, I., Islam, M. M., Ikushiro, H., Nakajima, Y., Hirotsu, K., and Kagamiyama, H. (2003) Biochim. Biophys. Acta1647, 103] as evidenced by the planarity of the pyridine ring and the Schiff base linkage with Lys258. Additionally, loss of this anchor causes a 10 degrees greater tilt of deazaPLP toward the substrate in the external aldimine. An important mechanistic difference between the l-aspartate.deazaPLP and alpha-methyl-l-aspartate.PLP external aldimines is a hydrogen bond between Gly38 and Lys258 in the former, positioning the catalytic base above and approximately equidistant between Calpha and C4'. In contrast, in the alpha-methyl-l-aspartate.PLP external aldimine, the epsilon-amino group of Lys258 is rotated approximately 70 degrees to form a hydrogen bond to Tyr70 because of the steric bulk of the methyl group. | ||
| - | + | Crystal Structures of Aspartate Aminotransferase Reconstituted with 1-Deazapyridoxal 5'-Phosphate: Internal Aldimine and Stable l-Aspartate External Aldimine.,Griswold WR, Fisher AJ, Toney MD Biochemistry. 2011 Jun 9. PMID:21627105<ref>PMID:21627105</ref> | |
| - | + | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |
| - | + | </div> | |
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==See Also== | ==See Also== | ||
*[[Aspartate Aminotransferase|Aspartate Aminotransferase]] | *[[Aspartate Aminotransferase|Aspartate Aminotransferase]] | ||
| - | + | == References == | |
| - | == | + | <references/> |
| - | < | + | __TOC__ |
| + | </StructureSection> | ||
[[Category: Aspartate transaminase]] | [[Category: Aspartate transaminase]] | ||
[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
| - | [[Category: Griswold, W R | + | [[Category: Griswold, W R]] |
[[Category: Aminotransferase]] | [[Category: Aminotransferase]] | ||
[[Category: Transferase]] | [[Category: Transferase]] | ||
Revision as of 10:51, 9 December 2014
Crystal Structures of Escherichia coli Aspartate Aminotransferase Reconstituted with 1-Deaza-Pyridoxal 5'-Phosphate: Internal Aldimine and Stable L-Aspartate External Aldimine
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