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==Crystal Structure of Helicobacter pylori gamma-Glutamyltranspeptidase== | |||
<StructureSection load='2nqo' size='340' side='right'caption='[[2nqo]], [[Resolution|resolution]] 1.90Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[2nqo]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Helicobacter_pylori Helicobacter pylori]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2NQO OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2NQO 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]] 1.9Å</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=2nqo FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2nqo OCA], [https://pdbe.org/2nqo PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2nqo RCSB], [https://www.ebi.ac.uk/pdbsum/2nqo PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2nqo ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/O25743_HELPY O25743_HELPY] | |||
== 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/nq/2nqo_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=2nqo ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Helicobacter pylorigamma-glutamyltranspeptidase (HpGT) is a glutathione-degrading enzyme that has been shown to be a virulence factor in infection. It is expressed as a 60-kDa inactive precursor that must undergo autocatalytic processing to generate a 40-kDa/20-kDa heterodimer with full gamma-glutamyl amide bond hydrolase activity. The new N terminus of the processed enzyme, Thr-380, is the catalytic nucleophile in both the autoprocessing and enzymatic reactions, indicating that HpGT is a member of the N-terminal nucleophile hydrolase superfamily. To further investigate activation as a result of autoprocessing, the structure of HpGT has been determined to a resolution of 1.9 A. The refined model contains two 40-kDa/20-kDa heterodimers in the asymmetric unit and has structural features comparable with other N-terminal nucleophile hydrolases. Autoprocessing of HpGT leads to a large conformational change, with the loop preceding the catalytic Thr-380 moving >35 A, thus relieving steric constraints that likely limit substrate binding. In addition, cleavage of the proenzyme results in the formation of a threonine-threonine dyad comprised of Thr-380 and a second conserved threonine residue, Thr-398. The hydroxyl group of Thr-398 is located equidistant from the alpha-amino group and hydroxyl side chain of Thr-380. Mutation of Thr-398 to an alanine results in an enzyme that is fully capable of autoprocessing but is devoid of enzymatic activity. Substrate docking studies in combination with homology modeling studies of the human homologue reveal additional mechanistic details of enzyme maturation and activation, substrate recognition, and catalysis. | |||
Autoprocessing of Helicobacter pylori gamma-glutamyltranspeptidase leads to the formation of a threonine-threonine catalytic dyad.,Boanca G, Sand A, Okada T, Suzuki H, Kumagai H, Fukuyama K, Barycki JJ J Biol Chem. 2007 Jan 5;282(1):534-41. Epub 2006 Nov 15. PMID:17107958<ref>PMID:17107958</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 2nqo" style="background-color:#fffaf0;"></div> | |||
== References == | |||
<references/> | |||
== | __TOC__ | ||
< | </StructureSection> | ||
[[Category: Helicobacter pylori]] | [[Category: Helicobacter pylori]] | ||
[[Category: Barycki | [[Category: Large Structures]] | ||
[[Category: Boanca | [[Category: Barycki JJ]] | ||
[[Category: Fukuyama | [[Category: Boanca G]] | ||
[[Category: Kumagai | [[Category: Fukuyama K]] | ||
[[Category: Okada | [[Category: Kumagai H]] | ||
[[Category: Sand | [[Category: Okada T]] | ||
[[Category: Suzuki | [[Category: Sand A]] | ||
[[Category: Suzuki H]] | |||
Latest revision as of 13:18, 30 August 2023
Crystal Structure of Helicobacter pylori gamma-GlutamyltranspeptidaseCrystal Structure of Helicobacter pylori gamma-Glutamyltranspeptidase
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 PubMedHelicobacter pylorigamma-glutamyltranspeptidase (HpGT) is a glutathione-degrading enzyme that has been shown to be a virulence factor in infection. It is expressed as a 60-kDa inactive precursor that must undergo autocatalytic processing to generate a 40-kDa/20-kDa heterodimer with full gamma-glutamyl amide bond hydrolase activity. The new N terminus of the processed enzyme, Thr-380, is the catalytic nucleophile in both the autoprocessing and enzymatic reactions, indicating that HpGT is a member of the N-terminal nucleophile hydrolase superfamily. To further investigate activation as a result of autoprocessing, the structure of HpGT has been determined to a resolution of 1.9 A. The refined model contains two 40-kDa/20-kDa heterodimers in the asymmetric unit and has structural features comparable with other N-terminal nucleophile hydrolases. Autoprocessing of HpGT leads to a large conformational change, with the loop preceding the catalytic Thr-380 moving >35 A, thus relieving steric constraints that likely limit substrate binding. In addition, cleavage of the proenzyme results in the formation of a threonine-threonine dyad comprised of Thr-380 and a second conserved threonine residue, Thr-398. The hydroxyl group of Thr-398 is located equidistant from the alpha-amino group and hydroxyl side chain of Thr-380. Mutation of Thr-398 to an alanine results in an enzyme that is fully capable of autoprocessing but is devoid of enzymatic activity. Substrate docking studies in combination with homology modeling studies of the human homologue reveal additional mechanistic details of enzyme maturation and activation, substrate recognition, and catalysis. Autoprocessing of Helicobacter pylori gamma-glutamyltranspeptidase leads to the formation of a threonine-threonine catalytic dyad.,Boanca G, Sand A, Okada T, Suzuki H, Kumagai H, Fukuyama K, Barycki JJ J Biol Chem. 2007 Jan 5;282(1):534-41. Epub 2006 Nov 15. PMID:17107958[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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