1ii2: Difference between revisions
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==Crystal Structure of Phosphoenolpyruvate Carboxykinase (PEPCK) from Trypanosoma cruzi== | |||
=== | <StructureSection load='1ii2' size='340' side='right' caption='[[1ii2]], [[Resolution|resolution]] 2.00Å' scene=''> | ||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[1ii2]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Trypanosoma_cruzi Trypanosoma cruzi]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1II2 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1II2 FirstGlance]. <br> | |||
</td></tr><tr><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene><br> | |||
<tr><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Phosphoenolpyruvate_carboxykinase_(GTP) Phosphoenolpyruvate carboxykinase (GTP)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.1.1.32 4.1.1.32] </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=1ii2 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ii2 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1ii2 RCSB], [http://www.ebi.ac.uk/pdbsum/1ii2 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/ii/1ii2_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 == | |||
ATP-dependent phosphoenolpyruvate carboxykinase (PEPCK) (ATP: oxaloacetate carboxylyase (transphosphorylating), EC 4.1.1.49) is a key enzyme involved in the catabolism of glucose and amino acids in the parasite Trypanosoma cruzi, the causative agent of Chagas' disease. Due to the significant differences in the amino acid sequence and substrate specificity of the human enzyme (PEPCK (GTP-dependent), EC 4.1.1.32), the parasite enzyme has been considered a good target for the development of new anti-chagasic drugs. We have solved the crystal structure of the recombinant PEPCK of T. cruzi up to 2.0 A resolution, characterised the dimeric organisation of the enzyme by solution small angle X-ray scattering (SAXS) and compared the enzyme structure with the known crystal structure of the monomeric PEPCK from Escherichia coli. The dimeric structure possesses 2-fold symmetry, with each monomer sharing a high degree of structural similarity with the monomeric structure of the E. coli PEPCK. Each monomer folds into two complex mixed alpha/beta domains, with the active site located in a deep cleft between the domains. The two active sites in the dimer are far apart from each other, in an arrangement that seems to permit an independent access of the substrates to the two active sites. All residues of the E. coli PEPCK structure that had been found to interact with substrates and metal cofactors have been found conserved and in a substantially equivalent spatial disposition in the T. cruzi PEPCK structure. No substrate or metal ion was present in the crystal structure. A sulphate ion from the crystallisation medium has been found bound to the active site. Solution SAXS data suggest that, in solutions with lower sulphate concentration than that used for the crystallisation experiments, the actual enzyme conformation may be slightly different from its conformation in the crystal structure. This could be due to a conformational transition upon sulphate binding, similar to the ATP-induced transition observed in the E. coli PEPCK, or to crystal packing effects. The present structure of the T. cruzi PEPCK will provide a good basis for the modelling of new anti-chagasic drug leads. | |||
Crystal structure of the dimeric phosphoenolpyruvate carboxykinase (PEPCK) from Trypanosoma cruzi at 2 A resolution.,Trapani S, Linss J, Goldenberg S, Fischer H, Craievich AF, Oliva G J Mol Biol. 2001 Nov 9;313(5):1059-72. PMID:11700062<ref>PMID:11700062</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
==See Also== | ==See Also== | ||
*[[Phosphoenolpyruvate carboxykinase|Phosphoenolpyruvate carboxykinase]] | *[[Phosphoenolpyruvate carboxykinase|Phosphoenolpyruvate carboxykinase]] | ||
== References == | |||
== | <references/> | ||
__TOC__ | |||
</StructureSection> | |||
[[Category: Trypanosoma cruzi]] | [[Category: Trypanosoma cruzi]] | ||
[[Category: Craievich, A F.]] | [[Category: Craievich, A F.]] | ||