|
|
| (5 intermediate revisions not shown.) |
| Line 1: |
Line 1: |
| | + | |
| | ==Crystal Structure of human GGT1 in complex with Serine Borate== | | ==Crystal Structure of human GGT1 in complex with Serine Borate== |
| - | <StructureSection load='4zc6' size='340' side='right' caption='[[4zc6]], [[Resolution|resolution]] 2.10Å' scene=''> | + | <StructureSection load='4zc6' size='340' side='right'caption='[[4zc6]], [[Resolution|resolution]] 2.10Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[4zc6]] is a 2 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4ZC6 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4ZC6 FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[4zc6]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4ZC6 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4ZC6 FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene>, <scene name='pdbligand=SEE:TRIHYDROXY(L-SERINATO-KAPPAO~3~)BORATE(1-)'>SEE</scene></td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.1Å</td></tr> |
| - | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4zc6 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4zc6 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4zc6 RCSB], [http://www.ebi.ac.uk/pdbsum/4zc6 PDBsum]</span></td></tr> | + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene>, <scene name='pdbligand=SEE:TRIHYDROXY(L-SERINATO-KAPPAO~3~)BORATE(1-)'>SEE</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=4zc6 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4zc6 OCA], [https://pdbe.org/4zc6 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4zc6 RCSB], [https://www.ebi.ac.uk/pdbsum/4zc6 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4zc6 ProSAT]</span></td></tr> |
| | </table> | | </table> |
| | == Disease == | | == Disease == |
| - | [[http://www.uniprot.org/uniprot/GGT1_HUMAN GGT1_HUMAN]] Gamma-glutamyl transpeptidase deficiency. The disease is caused by mutations affecting the gene represented in this entry. | + | [https://www.uniprot.org/uniprot/GGT1_HUMAN GGT1_HUMAN] Gamma-glutamyl transpeptidase deficiency. The disease is caused by mutations affecting the gene represented in this entry. |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/GGT1_HUMAN GGT1_HUMAN]] Initiates extracellular glutathione (GSH) breakdown, provides cells with a local cysteine supply and contributes to maintain intracellular GSH level. It is part of the cell antioxidant defense mechanism. Catalyzes the transfer of the glutamyl moiety of glutathione to amino acids and dipeptide acceptors. Alternatively, glutathione can be hydrolyzed to give Cys-Gly and gamma glutamate. Isoform 3 seems to be inactive.<ref>PMID:7689219</ref> <ref>PMID:20622017</ref> | + | [https://www.uniprot.org/uniprot/GGT1_HUMAN GGT1_HUMAN] Initiates extracellular glutathione (GSH) breakdown, provides cells with a local cysteine supply and contributes to maintain intracellular GSH level. It is part of the cell antioxidant defense mechanism. Catalyzes the transfer of the glutamyl moiety of glutathione to amino acids and dipeptide acceptors. Alternatively, glutathione can be hydrolyzed to give Cys-Gly and gamma glutamate. Isoform 3 seems to be inactive.<ref>PMID:7689219</ref> <ref>PMID:20622017</ref> |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
| - | The enzyme gamma-glutamyl transpeptidase 1 (GGT1) is a conserved member of the Nterminal nucleophile (Ntn)-hydroylase family that cleaves the gamma-glutamyl bond of glutathione and other gamma-glutamyl compounds. In animals, GGT1 is expressed on the surface of the cell and has critical roles in maintaining cysteine levels in the body and regulating intracellular redox status. Expression of GGT1 has been implicated as a potentiator of asthma, cardiovascular disease, and cancer. The rational design of effective inhibitors of human GGT1 (hGGT1) has been delayed by the lack of a reliable structural model. The available crystal structures of several bacterial GGTs have been of limited use due to differences in the catalytic behavior of bacterial and mammalian GGTs. We report the high-resolution (1.67 A) crystal structure of glutamate-bound hGGT1, the first of any eukaryotic GGT. Comparisons of the active site architecture of hGGT1 to those of its bacterial orthologs highlight key differences in the residues responsible for substrate binding, including a bimodal switch in the orientation of the catalytic nucleophile (Thr-381) that is unique to the human enzyme. Compared to several bacterial counterparts, the lid loop in the crystal structure of hGGT1 adopts an open conformation that allows greater access to the active site. The hGGT1 structure also revealed tightly bound chlorides near the catalytic residue that may contribute to catalytic activity. These are absent in the bacterial GGTs. These differences between bacterial and mammalian GGTs and the new structural data will accelerate the development of new therapies for GGT1-dependent diseases.
| + | Gamma-glutamyl transpeptidase 1 (GGT1) is a cell surface, N-terminal nucleophile hydrolase that cleaves glutathione and other gamma-glutamyl compounds. GGT1 expression is essential in cysteine homeostasis and its induction has been implicated in the pathology of asthma, reperfusion injury and cancer. In this study, we report four new crystal structures of human GGT1 (hGGT1) which show conformational changes within the active site as the enzyme progresses from the free enzyme to inhibitor-bound tetrahedral transition states and finally to the glutamate-bound structure prior to the release of this final product of the reaction. The structure of the apo-enzyme shows flexibility within the active site. The serine-borate-bound hGGT1 crystal structure demonstrates that serine-borate occupies the active site of enzyme resulting in an enzyme-inhibitor complex that replicates the enzymes tetrahedral intermediate/transition state. The structure of GGsTop-bound hGGT1 reveals its interactions with the enzyme and why neutral phosphonate diesters are more potent inhibitors than mono-anionic phosphonates. These structures are the first structures for any eukaryotic GGT that include a molecule in the active site covalently bound to the catalytic Thr381. The glutamate-bound structure shows the conformation of the enzyme prior to release of the final product and revealed novel information regarding the displacement of the main chain atoms that form the oxyanion hole and movement of the lid loop region when the active site is occupied. These data provide new insights into the mechanism of hGGT1-catalyzed reactions and will be invaluable in the development of new classes of hGGT1 inhibitors for therapeutic use. |
| | | | |
| - | Novel insights into eukaryotic gamma-glutamyl transpeptidase 1 from the crystal structure of the glutamate-bound human enzyme.,West MB, Chen Y, Wickham S, Heroux A, Cahill K, Hanigan MH, Mooers BH J Biol Chem. 2013 Sep 18. PMID:24047895<ref>PMID:24047895</ref>
| + | Human Gamma-Glutamyl Transpeptidase 1: Structures of the Free Enzyme, Inhibitor-Bound Tetrahedral Transition States and Glutamate-Bound Enzyme Reveal Novel Movement within the Active Site during Catalysis.,Terzyan SS, Burgett AW, Heroux A, Smith CA, Mooers BH, Hanigan MH J Biol Chem. 2015 May 26. pii: jbc.M115.659680. PMID:26013825<ref>PMID:26013825</ref> |
| | | | |
| | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> |
| | </div> | | </div> |
| | + | <div class="pdbe-citations 4zc6" style="background-color:#fffaf0;"></div> |
| | == References == | | == References == |
| | <references/> | | <references/> |
| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Hanigan, M]] | + | [[Category: Homo sapiens]] |
| - | [[Category: Terzyan, S]] | + | [[Category: Large Structures]] |
| - | [[Category: Cell surface]] | + | [[Category: Hanigan M]] |
| - | [[Category: Glycoprotein]] | + | [[Category: Terzyan S]] |
| - | [[Category: Hydrolase]]
| + | |
| - | [[Category: Hydrolase-hydrolase inhibitor complex]]
| + | |
| - | [[Category: N- glycosylation]]
| + | |
| - | [[Category: Ntn-hydrolase family]]
| + | |
| Structural highlights
Disease
GGT1_HUMAN Gamma-glutamyl transpeptidase deficiency. The disease is caused by mutations affecting the gene represented in this entry.
Function
GGT1_HUMAN Initiates extracellular glutathione (GSH) breakdown, provides cells with a local cysteine supply and contributes to maintain intracellular GSH level. It is part of the cell antioxidant defense mechanism. Catalyzes the transfer of the glutamyl moiety of glutathione to amino acids and dipeptide acceptors. Alternatively, glutathione can be hydrolyzed to give Cys-Gly and gamma glutamate. Isoform 3 seems to be inactive.[1] [2]
Publication Abstract from PubMed
Gamma-glutamyl transpeptidase 1 (GGT1) is a cell surface, N-terminal nucleophile hydrolase that cleaves glutathione and other gamma-glutamyl compounds. GGT1 expression is essential in cysteine homeostasis and its induction has been implicated in the pathology of asthma, reperfusion injury and cancer. In this study, we report four new crystal structures of human GGT1 (hGGT1) which show conformational changes within the active site as the enzyme progresses from the free enzyme to inhibitor-bound tetrahedral transition states and finally to the glutamate-bound structure prior to the release of this final product of the reaction. The structure of the apo-enzyme shows flexibility within the active site. The serine-borate-bound hGGT1 crystal structure demonstrates that serine-borate occupies the active site of enzyme resulting in an enzyme-inhibitor complex that replicates the enzymes tetrahedral intermediate/transition state. The structure of GGsTop-bound hGGT1 reveals its interactions with the enzyme and why neutral phosphonate diesters are more potent inhibitors than mono-anionic phosphonates. These structures are the first structures for any eukaryotic GGT that include a molecule in the active site covalently bound to the catalytic Thr381. The glutamate-bound structure shows the conformation of the enzyme prior to release of the final product and revealed novel information regarding the displacement of the main chain atoms that form the oxyanion hole and movement of the lid loop region when the active site is occupied. These data provide new insights into the mechanism of hGGT1-catalyzed reactions and will be invaluable in the development of new classes of hGGT1 inhibitors for therapeutic use.
Human Gamma-Glutamyl Transpeptidase 1: Structures of the Free Enzyme, Inhibitor-Bound Tetrahedral Transition States and Glutamate-Bound Enzyme Reveal Novel Movement within the Active Site during Catalysis.,Terzyan SS, Burgett AW, Heroux A, Smith CA, Mooers BH, Hanigan MH J Biol Chem. 2015 May 26. pii: jbc.M115.659680. PMID:26013825[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Wetmore LA, Gerard C, Drazen JM. Human lung expresses unique gamma-glutamyl transpeptidase transcripts. Proc Natl Acad Sci U S A. 1993 Aug 15;90(16):7461-5. PMID:7689219
- ↑ West MB, Segu ZM, Feasley CL, Kang P, Klouckova I, Li C, Novotny MV, West CM, Mechref Y, Hanigan MH. Analysis of site-specific glycosylation of renal and hepatic gamma-glutamyl transpeptidase from normal human tissue. J Biol Chem. 2010 Sep 17;285(38):29511-24. doi: 10.1074/jbc.M110.145938. Epub, 2010 Jul 9. PMID:20622017 doi:10.1074/jbc.M110.145938
- ↑ Terzyan SS, Burgett AW, Heroux A, Smith CA, Mooers BH, Hanigan MH. Human Gamma-Glutamyl Transpeptidase 1: Structures of the Free Enzyme, Inhibitor-Bound Tetrahedral Transition States and Glutamate-Bound Enzyme Reveal Novel Movement within the Active Site during Catalysis. J Biol Chem. 2015 May 26. pii: jbc.M115.659680. PMID:26013825 doi:http://dx.doi.org/10.1074/jbc.M115.659680
|
