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==The crystal structure of a dimeric mutant of Dihydrodipicolinate synthase from E.coli- DHDPS-L197Y== | ==The crystal structure of a dimeric mutant of Dihydrodipicolinate synthase from E.coli- DHDPS-L197Y== | ||
<StructureSection load='2ojp' size='340' side='right' caption='[[2ojp]], [[Resolution|resolution]] 1.70Å' scene=''> | <StructureSection load='2ojp' size='340' side='right' caption='[[2ojp]], [[Resolution|resolution]] 1.70Å' scene=''> | ||
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<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">dapA ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 "Bacillus coli" Migula 1895])</td></tr> | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">dapA ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 "Bacillus coli" Migula 1895])</td></tr> | ||
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/4-hydroxy-tetrahydrodipicolinate_synthase 4-hydroxy-tetrahydrodipicolinate synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.3.3.7 4.3.3.7] </span></td></tr> | <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/4-hydroxy-tetrahydrodipicolinate_synthase 4-hydroxy-tetrahydrodipicolinate synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.3.3.7 4.3.3.7] </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=2ojp FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2ojp OCA], [http://pdbe.org/2ojp PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=2ojp RCSB], [http://www.ebi.ac.uk/pdbsum/2ojp PDBsum]</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=2ojp FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2ojp OCA], [http://pdbe.org/2ojp PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=2ojp RCSB], [http://www.ebi.ac.uk/pdbsum/2ojp PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=2ojp ProSAT]</span></td></tr> | ||
</table> | </table> | ||
== Function == | == Function == | ||
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<text>to colour the structure by Evolutionary Conservation</text> | <text>to colour the structure by Evolutionary Conservation</text> | ||
</jmolCheckbox> | </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/ | </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=2ojp ConSurf]. | ||
<div style="clear:both"></div> | <div style="clear:both"></div> | ||
<div style="background-color:#fffaf0;"> | <div style="background-color:#fffaf0;"> | ||
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</div> | </div> | ||
<div class="pdbe-citations 2ojp" style="background-color:#fffaf0;"></div> | <div class="pdbe-citations 2ojp" style="background-color:#fffaf0;"></div> | ||
== References == | == References == | ||
<references/> | <references/> | ||
Revision as of 12:02, 18 October 2017
The crystal structure of a dimeric mutant of Dihydrodipicolinate synthase from E.coli- DHDPS-L197YThe crystal structure of a dimeric mutant of Dihydrodipicolinate synthase from E.coli- DHDPS-L197Y
Structural highlights
Function[DAPA_ECOLI] Catalyzes the condensation of (S)-aspartate-beta-semialdehyde [(S)-ASA] and pyruvate to 4-hydroxy-tetrahydrodipicolinate (HTPA).[1] [2] 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 PubMedDihydrodipicolinate synthase (DHDPS) is an essential enzyme in (S)-lysine biosynthesis and an important antibiotic target. All X-ray crystal structures solved to date reveal a homotetrameric enzyme. In order to explore the role of this quaternary structure, dimeric variants of Escherichia coli DHDPS were engineered and their properties were compared to those of the wild-type tetrameric form. X-ray crystallography reveals that the active site is not disturbed when the quaternary structure is disrupted. However, the activity of the dimeric enzymes in solution is substantially reduced, and a tetrahedral adduct of a substrate analogue is observed to be trapped at the active site in the crystal form. Remarkably, heating the dimeric enzymes increases activity. We propose that the homotetrameric structure of DHDPS reduces dynamic fluctuations present in the dimeric forms and increases specificity for the first substrate, pyruvate. By restricting motion in a key catalytic motif, a competing, non-productive reaction with a substrate analogue is avoided. Small-angle X-ray scattering and mutagenesis data, together with a B-factor analysis of the crystal structures, support this hypothesis and lead to the suggestion that in at least some cases, the evolution of quaternary enzyme structures might serve to optimise the dynamic properties of the protein subunits. Evolution of quaternary structure in a homotetrameric enzyme.,Griffin MD, Dobson RC, Pearce FG, Antonio L, Whitten AE, Liew CK, Mackay JP, Trewhella J, Jameson GB, Perugini MA, Gerrard JA J Mol Biol. 2008 Jul 18;380(4):691-703. Epub 2008 May 22. PMID:18556019[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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