2qmc
From Proteopedia
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| - | [[Image:2qmc.jpg|left|200px]] | + | [[Image:2qmc.jpg|left|200px]] |
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| - | '''Crystal Structure of Helicobacter Pylori Gamma-Glutamyltranspeptidase T380A Mutant''' | + | {{Structure |
| + | |PDB= 2qmc |SIZE=350|CAPTION= <scene name='initialview01'>2qmc</scene>, resolution 1.550Å | ||
| + | |SITE= <scene name='pdbsite=AC1:Gtb+Binding+Site+For+Residue+B+1'>AC1</scene> and <scene name='pdbsite=AC2:Gtb+Binding+Site+For+Residue+D+1'>AC2</scene> | ||
| + | |LIGAND= <scene name='pdbligand=GTB:S-(P-NITROBENZYL)GLUTATHIONE'>GTB</scene> | ||
| + | |ACTIVITY= [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] | ||
| + | |GENE= HP_1118 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=210 Helicobacter pylori]) | ||
| + | }} | ||
| + | |||
| + | '''Crystal Structure of Helicobacter Pylori Gamma-Glutamyltranspeptidase T380A Mutant''' | ||
| + | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
| - | 2QMC is a [ | + | 2QMC is a [[Protein complex]] structure of sequences 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]. |
==Reference== | ==Reference== | ||
| - | 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:[http:// | + | 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:[http://www.ncbi.nlm.nih.gov/pubmed/17960917 17960917] |
[[Category: Gamma-glutamyltransferase]] | [[Category: Gamma-glutamyltransferase]] | ||
[[Category: Helicobacter pylori]] | [[Category: Helicobacter pylori]] | ||
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[[Category: transferase]] | [[Category: transferase]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 18:27:22 2008'' |
Revision as of 16:27, 20 March 2008
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| , resolution 1.550Å | |||||||
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| Sites: | and | ||||||
| Ligands: | |||||||
| Gene: | HP_1118 (Helicobacter pylori) | ||||||
| Activity: | Gamma-glutamyltransferase, with EC number 2.3.2.2 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Crystal Structure of Helicobacter Pylori Gamma-Glutamyltranspeptidase T380A Mutant
Overview
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.
About this Structure
2QMC is a Protein complex structure of sequences from Helicobacter pylori. Full crystallographic information is available from OCA.
Reference
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
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