This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
2qmc
From Proteopedia
(Difference between revisions)
| Line 1: | Line 1: | ||
| - | [[ | + | ==Crystal Structure of Helicobacter Pylori Gamma-Glutamyltranspeptidase T380A Mutant== |
| + | <StructureSection load='2qmc' size='340' side='right' caption='[[2qmc]], [[Resolution|resolution]] 1.55Å' scene=''> | ||
| + | == Structural highlights == | ||
| + | <table><tr><td colspan='2'>[[2qmc]] is a 4 chain structure with sequence from [http://en.wikipedia.org/wiki/Helicobacter_pylori Helicobacter pylori]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2QMC OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2QMC FirstGlance]. <br> | ||
| + | </td></tr><tr><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=GTB:S-(P-NITROBENZYL)GLUTATHIONE'>GTB</scene><br> | ||
| + | <tr><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[2nqo|2nqo]], [[2qm6|2qm6]]</td></tr> | ||
| + | <tr><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">HP_1118 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=210 Helicobacter pylori])</td></tr> | ||
| + | <tr><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Gamma-glutamyltransferase Gamma-glutamyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.3.2.2 2.3.2.2] </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=2qmc FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2qmc OCA], [http://www.rcsb.org/pdb/explore.do?structureId=2qmc RCSB], [http://www.ebi.ac.uk/pdbsum/2qmc 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/qm/2qmc_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 == | ||
| + | Helicobacter pylori gamma-glutamyltranspeptidase (HpGT) is a member of the N-terminal nucleophile hydrolase superfamily. It is translated as an inactive 60 kDa polypeptide precursor that undergoes intramolecular autocatalytic cleavage to generate a fully active heterodimer composed of a 40 kDa and a 20 kDa subunit. The resultant N-terminus, Thr 380, has been shown to be the catalytic nucleophile in both autoprocessing and enzymatic reactions. Once processed, HpGT catalyzes the hydrolysis of the gamma-glutamyl bond in glutathione and its conjugates. To facilitate the determination of physiologically relevant substrates for the enzyme, crystal structures of HpGT in complex with glutamate (1.6 A, Rfactor = 16.7%, Rfree = 19.0%) and an inactive HpGT mutant, T380A, in complex with S-(nitrobenzyl)glutathione (1.55 A, Rfactor = 18.7%, Rfree = 21.8%) have been determined. Residues that comprise the gamma-glutamyl binding site are primarily located in the 20 kDa subunit and make numerous hydrogen bonds with the alpha-amino and alpha-carboxylate groups of the substrate. In contrast, a single hydrogen bond occurs between the T380A mutant and the remainder of the ligand. Lack of specific coordination beyond the gamma-glutamyl moiety may account for the substrate binding permissiveness of the enzyme. Structural analysis was combined with site-directed mutagenesis of residues involved in maintaining the conformation of a loop region that covers the gamma-glutamyl binding site. Results provide evidence that access to this buried site may occur through conformational changes in the Tyr 433-containing loop, as disruption of the intricate hydrogen-bond network responsible for optimal placement of Tyr 433 significantly diminishes catalytic activity. | ||
| - | + | Characterization of Helicobacter pylori gamma-glutamyltranspeptidase reveals the molecular basis for substrate specificity and a critical role for the tyrosine 433-containing loop in catalysis.,Morrow AL, Williams K, Sand A, Boanca G, Barycki JJ Biochemistry. 2007 Nov 20;46(46):13407-14. Epub 2007 Oct 26. PMID:17960917<ref>PMID:17960917</ref> | |
| - | + | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |
| - | + | </div> | |
| - | + | == References == | |
| - | + | <references/> | |
| - | + | __TOC__ | |
| - | + | </StructureSection> | |
| - | + | ||
| - | == | + | |
| - | < | + | |
[[Category: Gamma-glutamyltransferase]] | [[Category: Gamma-glutamyltransferase]] | ||
[[Category: Helicobacter pylori]] | [[Category: Helicobacter pylori]] | ||
Revision as of 18:22, 30 September 2014
Crystal Structure of Helicobacter Pylori Gamma-Glutamyltranspeptidase T380A Mutant
| |||||||||||
