4c1k: Difference between revisions
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==Crystal structure of pyrococcus furiosus 3-deoxy-D-arabino- heptulosonate 7-phosphate synthase== | |||
<StructureSection load='4c1k' size='340' side='right'caption='[[4c1k]], [[Resolution|resolution]] 2.15Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[4c1k]] is a 6 chain structure with sequence from [https://en.wikipedia.org/wiki/Pyrococcus_furiosus Pyrococcus furiosus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4C1K OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4C1K FirstGlance]. <br> | |||
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.15Å</td></tr> | |||
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=2PE:NONAETHYLENE+GLYCOL'>2PE</scene>, <scene name='pdbligand=CD:CADMIUM+ION'>CD</scene>, <scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=CO3:CARBONATE+ION'>CO3</scene>, <scene name='pdbligand=PEP:PHOSPHOENOLPYRUVATE'>PEP</scene></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=4c1k FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4c1k OCA], [https://pdbe.org/4c1k PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4c1k RCSB], [https://www.ebi.ac.uk/pdbsum/4c1k PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4c1k ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/Q8U0A9_PYRFU Q8U0A9_PYRFU] | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Many proteins adopt homomeric quaternary structures to support their biological function, including the first enzyme of the shikimate pathway that is ultimately responsible for the biosynthesis of the aromatic amino acids in plants and microorganisms. This enzyme, 3-deoxy-d-arabino-heptulosonate-7-phosphate synthase (DAH7PS), adopts a variety of different quaternary structures depending on the organism in which it is found. The DAH7PS from the hyperthermophilic archaebacterium Pyrococcus furiosus was previously shown to be tetrameric in its crystalline form, and this quaternary association is confirmed in an improved structure in a different crystal system. This tetramer is also present in solution as revealed by small-angle X-ray scattering and analytical ultracentrifugation. This homotetrameric form has two distinct interfaces, both of which bury over 10% each of the surface area of a single monomer. Substitution of Ile for Asp in the hydrophobic region of one interface gives a protein with a remarkable 4-fold higher maximum catalytic rate than the wild-type enzyme. Analytical ultracentrifugation at pH7.5 reveals that the tetrameric form is destabilized; although the protein crystallizes as a tetramer, equilibrium exists between tetrameric and dimeric forms with a dissociation constant of 22muM. Thus, under the conditions of kinetic assay, the enzyme is primarily dimeric, revealing that the dimeric form is a fully functional catalyst. However, in comparison to the wild-type protein, the thermal stability of the dimeric protein is significantly compromised. Thus, an unusual compromise of enzymatic activity versus stability is observed for this DAH7PS from an organism that favors a hyperthermophilic environment. | |||
Destabilization of the Homotetrameric Assembly of 3-Deoxy-d-Arabino-Heptulosonate-7-Phosphate Synthase from the Hyperthermophile Pyrococcus furiosus Enhances Enzymatic Activity.,Nazmi AR, Schofield LR, Dobson RC, Jameson GB, Parker EJ J Mol Biol. 2013 Nov 14. pii: S0022-2836(13)00719-5. doi:, 10.1016/j.jmb.2013.11.008. PMID:24239948<ref>PMID:24239948</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 4c1k" style="background-color:#fffaf0;"></div> | |||
==See Also== | |||
*[[DAHP synthase 3D structures|DAHP synthase 3D structures]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Large Structures]] | |||
[[Category: Pyrococcus furiosus]] | |||
[[Category: Dobson RCJ]] | |||
[[Category: Jameson GB]] | |||
[[Category: Nazmi AR]] | |||
[[Category: Parker EJ]] | |||
[[Category: Schofield LR]] | |||