|
|
| (2 intermediate revisions not shown.) |
| Line 1: |
Line 1: |
| | + | |
| | ==Structure of dihydrodipicolinate synthase mutant Thr44Ser at 1.7 A.== | | ==Structure of dihydrodipicolinate synthase mutant Thr44Ser at 1.7 A.== |
| - | <StructureSection load='2pur' size='340' side='right' caption='[[2pur]], [[Resolution|resolution]] 1.70Å' scene=''> | + | <StructureSection load='2pur' size='340' side='right'caption='[[2pur]], [[Resolution|resolution]] 1.70Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[2pur]] is a 2 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=2PUR OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2PUR FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[2pur]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2PUR OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2PUR FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=K:POTASSIUM+ION'>K</scene>, <scene name='pdbligand=PO4:PHOSPHATE+ION'>PO4</scene></td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.7Å</td></tr> |
| - | <tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=KGC:N~6~-[(2R)-2-CARBOXY-5-OXOTETRAHYDROFURAN-2-YL]-L-LYSINE'>KGC</scene></td></tr> | + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=K:POTASSIUM+ION'>K</scene>, <scene name='pdbligand=KGC:N~6~-[(2R)-2-CARBOXY-5-OXOTETRAHYDROFURAN-2-YL]-L-LYSINE'>KGC</scene>, <scene name='pdbligand=PO4:PHOSPHATE+ION'>PO4</scene></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 Escherichia coli])</td></tr>
| + | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=2pur FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2pur OCA], [https://pdbe.org/2pur PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2pur RCSB], [https://www.ebi.ac.uk/pdbsum/2pur PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2pur ProSAT]</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=2pur FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2pur OCA], [http://pdbe.org/2pur PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=2pur RCSB], [http://www.ebi.ac.uk/pdbsum/2pur PDBsum]</span></td></tr> | + | |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/DAPA_ECOLI DAPA_ECOLI]] Catalyzes the condensation of (S)-aspartate-beta-semialdehyde [(S)-ASA] and pyruvate to 4-hydroxy-tetrahydrodipicolinate (HTPA).<ref>PMID:20503968</ref> <ref>PMID:8993314</ref> | + | [https://www.uniprot.org/uniprot/DAPA_ECOLI DAPA_ECOLI] Catalyzes the condensation of (S)-aspartate-beta-semialdehyde [(S)-ASA] and pyruvate to 4-hydroxy-tetrahydrodipicolinate (HTPA).<ref>PMID:20503968</ref> <ref>PMID:8993314</ref> |
| | == Evolutionary Conservation == | | == Evolutionary Conservation == |
| | [[Image:Consurf_key_small.gif|200px|right]] | | [[Image:Consurf_key_small.gif|200px|right]] |
| | Check<jmol> | | Check<jmol> |
| | <jmolCheckbox> | | <jmolCheckbox> |
| - | <scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/pu/2pur_consurf.spt"</scriptWhenChecked> | + | <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/pu/2pur_consurf.spt"</scriptWhenChecked> |
| | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> |
| | <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/chain_selection.php?pdb_ID=2ata ConSurf]. | + | </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=2pur ConSurf]. |
| | <div style="clear:both"></div> | | <div style="clear:both"></div> |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
| Line 37: |
Line 36: |
| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: 4-hydroxy-tetrahydrodipicolinate synthase]] | |
| | [[Category: Escherichia coli]] | | [[Category: Escherichia coli]] |
| - | [[Category: Dobson, R C.J]] | + | [[Category: Large Structures]] |
| - | [[Category: Gerrard, J A]] | + | [[Category: Dobson RCJ]] |
| - | [[Category: Jameson, G B]] | + | [[Category: Gerrard JA]] |
| - | [[Category: Lyase]] | + | [[Category: Jameson GB]] |
| - | [[Category: Tim barrel]]
| + | |
| 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 PubMed
In plants and bacteria, the branch point of (S)-lysine biosynthesis is the condensation of (S)-aspartate-beta-semialdehyde and pyruvate, a reaction catalysed by dihydrodipicolinate synthase (DHDPS, E.C. 4.2.1.52). In this study, we probe the function of threonine 44 in Escherichia coli DHDPS, with respect to its role in the proton relay. Removal of the hydroxyl moiety of threonine 44, by mutation to valine, significantly attenuates activity (0.1% of wild-type) because the proton relay is broken. It was thus predicted that mutation of threonine 44 to serine would re-establish the proton relay and thus enzymatic activity. Following site-directed mutagenesis and purification to yield the DHDPS-Thr44Ser mutant enzyme, kinetic and structural studies were undertaken. The crystal structure of DHDPS-Thr44Ser showed that the active site was intact and that Ser44 and Tyr107 have some conformational flexibility, which is consistent with the observed loss of activity compared to the wild-type enzyme. Electron density was observed at the active site of DHDPS-Thr44Ser, which was identified as a trapped pyruvate analogue, alpha-ketoglutarate. The activity was indeed found to be increased relative to DHDPS-Thr44Val, but was still reduced to only approximately 8% of that of the wild-type enzyme. Interestingly, there was a shift in the kinetic mechanism, from the substituted-enzyme mechanism, observed in the wild-type, to the ternary-complex mechanism, consistent with the trapped substrate analogue. Increased flexibility in the active site appears to facilitate the binding/reaction of substrate analogues, suggesting that wild-type DHDPS has evolved a relatively rigid active site in order to maintain substrate specificity for pyruvate.
Specificity versus catalytic potency: The role of threonine 44 in Escherichia coli dihydrodipicolinate synthase mediated catalysis.,Dobson RC, Perugini MA, Jameson GB, Gerrard JA Biochimie. 2009 Aug;91(8):1036-44. Epub 2009 Jun 6. PMID:19505526[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Devenish SR, Blunt JW, Gerrard JA. NMR studies uncover alternate substrates for dihydrodipicolinate synthase and suggest that dihydrodipicolinate reductase is also a dehydratase. J Med Chem. 2010 Jun 24;53(12):4808-12. doi: 10.1021/jm100349s. PMID:20503968 doi:10.1021/jm100349s
- ↑ Blickling S, Renner C, Laber B, Pohlenz HD, Holak TA, Huber R. Reaction mechanism of Escherichia coli dihydrodipicolinate synthase investigated by X-ray crystallography and NMR spectroscopy. Biochemistry. 1997 Jan 7;36(1):24-33. PMID:8993314 doi:10.1021/bi962272d
- ↑ Dobson RC, Perugini MA, Jameson GB, Gerrard JA. Specificity versus catalytic potency: The role of threonine 44 in Escherichia coli dihydrodipicolinate synthase mediated catalysis. Biochimie. 2009 Aug;91(8):1036-44. Epub 2009 Jun 6. PMID:19505526 doi:10.1016/j.biochi.2009.05.013
|
