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==Structure of Giardia fructose-1,6-biphosphate aldolase in complex with phosphoglycolohydroxamate== | |||
<StructureSection load='2isw' size='340' side='right'caption='[[2isw]], [[Resolution|resolution]] 1.75Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[2isw]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Giardia_intestinalis Giardia intestinalis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2ISW OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2ISW 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]] 1.75Å</td></tr> | |||
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=PGH:PHOSPHOGLYCOLOHYDROXAMIC+ACID'>PGH</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</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=2isw FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2isw OCA], [https://pdbe.org/2isw PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2isw RCSB], [https://www.ebi.ac.uk/pdbsum/2isw PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2isw ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/A8B2U2_GIAIC A8B2U2_GIAIC] | |||
== 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/is/2isw_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/main_output.php?pdb_ID=2isw ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Class I and class II fructose-1,6-bisphosphate aldolases (FBPA), glycolytic pathway enzymes, exhibit no amino acid sequence homology and utilize two different catalytic mechanisms. The mammalian class I FBPA employs a Schiff base mechanism, whereas the human parasitic protozoan Giardia lamblia class II FBPA is a zinc-dependent enzyme. In this study, we have explored the potential exploitation of the Giardia FBPA as a drug target. First, synthesis of FBPA was demonstrated in Giardia trophozoites by using an antibody-based fluorescence assay. Second, inhibition of FBPA gene transcription in Giardia trophozoites suggested that the enzyme is necessary for the survival of the organism under optimal laboratory growth conditions. Third, two crystal structures of FBPA in complex with the transition state analog phosphoglycolohydroxamate (PGH) show that the enzyme is homodimeric and that its active site contains a zinc ion. In one crystal form, each subunit contains PGH, which is coordinated to the zinc ion through the hydroxamic acid hydroxyl and carbonyl oxygen atoms. The second crystal form contains PGH only in one subunit and the active site of the second subunit is unoccupied. Inspection of the two states of the enzyme revealed that it undergoes a conformational transition upon ligand binding. The enzyme cleaves d-fructose-1,6-bisphosphate but not d-tagatose-1,6-bisphosphate, which is a tight binding competitive inhibitor. The essential role of the active site residue Asp-83 in catalysis was demonstrated by amino acid replacement. Determinants of catalysis and substrate recognition, derived from comparison of the G. lamblia FBPA structure with Escherichia coli FBPA and with a closely related enzyme, E. coli tagatose-1,6-bisphosphate aldolase (TBPA), are described. | |||
Characterization, kinetics, and crystal structures of fructose-1,6-bisphosphate aldolase from the human parasite, Giardia lamblia.,Galkin A, Kulakova L, Melamud E, Li L, Wu C, Mariano P, Dunaway-Mariano D, Nash TE, Herzberg O J Biol Chem. 2007 Feb 16;282(7):4859-67. Epub 2006 Dec 13. PMID:17166851<ref>PMID:17166851</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 2isw" style="background-color:#fffaf0;"></div> | |||
==See Also== | ==See Also== | ||
*[[Aldolase|Aldolase]] | *[[Aldolase 3D structures|Aldolase 3D structures]] | ||
== References == | |||
== | <references/> | ||
< | __TOC__ | ||
</StructureSection> | |||
[[Category: Giardia intestinalis]] | [[Category: Giardia intestinalis]] | ||
[[Category: | [[Category: Large Structures]] | ||
[[Category: | [[Category: Galkin A]] | ||
[[Category: | [[Category: Herzberg O]] | ||
Latest revision as of 13:15, 30 August 2023
Structure of Giardia fructose-1,6-biphosphate aldolase in complex with phosphoglycolohydroxamateStructure of Giardia fructose-1,6-biphosphate aldolase in complex with phosphoglycolohydroxamate
Structural highlights
FunctionEvolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedClass I and class II fructose-1,6-bisphosphate aldolases (FBPA), glycolytic pathway enzymes, exhibit no amino acid sequence homology and utilize two different catalytic mechanisms. The mammalian class I FBPA employs a Schiff base mechanism, whereas the human parasitic protozoan Giardia lamblia class II FBPA is a zinc-dependent enzyme. In this study, we have explored the potential exploitation of the Giardia FBPA as a drug target. First, synthesis of FBPA was demonstrated in Giardia trophozoites by using an antibody-based fluorescence assay. Second, inhibition of FBPA gene transcription in Giardia trophozoites suggested that the enzyme is necessary for the survival of the organism under optimal laboratory growth conditions. Third, two crystal structures of FBPA in complex with the transition state analog phosphoglycolohydroxamate (PGH) show that the enzyme is homodimeric and that its active site contains a zinc ion. In one crystal form, each subunit contains PGH, which is coordinated to the zinc ion through the hydroxamic acid hydroxyl and carbonyl oxygen atoms. The second crystal form contains PGH only in one subunit and the active site of the second subunit is unoccupied. Inspection of the two states of the enzyme revealed that it undergoes a conformational transition upon ligand binding. The enzyme cleaves d-fructose-1,6-bisphosphate but not d-tagatose-1,6-bisphosphate, which is a tight binding competitive inhibitor. The essential role of the active site residue Asp-83 in catalysis was demonstrated by amino acid replacement. Determinants of catalysis and substrate recognition, derived from comparison of the G. lamblia FBPA structure with Escherichia coli FBPA and with a closely related enzyme, E. coli tagatose-1,6-bisphosphate aldolase (TBPA), are described. Characterization, kinetics, and crystal structures of fructose-1,6-bisphosphate aldolase from the human parasite, Giardia lamblia.,Galkin A, Kulakova L, Melamud E, Li L, Wu C, Mariano P, Dunaway-Mariano D, Nash TE, Herzberg O J Biol Chem. 2007 Feb 16;282(7):4859-67. Epub 2006 Dec 13. PMID:17166851[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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