| Structural highlights
3vln is a 1 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
| | Ligands: | , , , , |
| Related: | 1eem, 3q18, 3q19, 3qag |
| Gene: | GSTO1, GSTTLP28 (Homo sapiens) |
| Activity: | Glutathione transferase, with EC number 2.5.1.18 |
| Resources: | FirstGlance, OCA, RCSB, PDBsum |
Function
[GSTO1_HUMAN] Exhibits glutathione-dependent thiol transferase and dehydroascorbate reductase activities. Has S-(phenacyl)glutathione reductase activity. Has also glutathione S-transferase activity. Participates in the biotransformation of inorganic arsenic and reduces monomethylarsonic acid (MMA) and dimethylarsonic acid.[1] [2] [3] [4] [5]
Publication Abstract from PubMed
The reduction of dehydroascorbate (DHA) to ascorbic acid (AA) is a vital cellular function. The omega-class glutathione S-transferases (GSTs) catalyze several reductive reactions in cellular biochemistry, including DHA reduction. In humans, two isozymes (GSTO1-1 and GSTO2-2) with significant DHA reductase (DHAR) activity are found, sharing 64% sequence identity. While the activity of GSTO2-2 is higher, it is significantly more unstable in vitro. We report the first crystal structures of human GSTO2-2, stabilized through site-directed mutagenesis and determined at 1.9 A resolution in the presence and absence of glutathione (GSH). The structure of a human GSTO1-1 has been determined at 1.7 A resolution in complex with the reaction product AA, which unexpectedly binds in the G-site, where the glutamyl moiety of GSH binds. The structure suggests a similar mode of ascorbate binding in GSTO2-2. This is the first time that a non-GSH-based reaction product has been observed in the G-site of any GST. AA stacks against a conserved aromatic residue, F34 (equivalent to Y34 in GSTO2-2). Mutation of Y34 to alanine in GSTO2-2 eliminates DHAR activity. From these structures and other biochemical data, we propose a mechanism of substrate binding and catalysis of DHAR activity.
Structural Insights into the Dehydroascorbate Reductase Activity of Human Omega-Class Glutathione Transferases.,Zhou H, Brock J, Liu D, Board PG, Oakley AJ J Mol Biol. 2012 Apr 18. PMID:22522127[6]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Board PG, Coggan M, Chelvanayagam G, Easteal S, Jermiin LS, Schulte GK, Danley DE, Hoth LR, Griffor MC, Kamath AV, Rosner MH, Chrunyk BA, Perregaux DE, Gabel CA, Geoghegan KF, Pandit J. Identification, characterization, and crystal structure of the Omega class glutathione transferases. J Biol Chem. 2000 Aug 11;275(32):24798-806. PMID:10783391 doi:10.1074/jbc.M001706200
- ↑ Zakharyan RA, Sampayo-Reyes A, Healy SM, Tsaprailis G, Board PG, Liebler DC, Aposhian HV. Human monomethylarsonic acid (MMA(V)) reductase is a member of the glutathione-S-transferase superfamily. Chem Res Toxicol. 2001 Aug;14(8):1051-7. PMID:11511179
- ↑ Board PG, Anders MW. Glutathione transferase omega 1 catalyzes the reduction of S-(phenacyl)glutathiones to acetophenones. Chem Res Toxicol. 2007 Jan;20(1):149-54. PMID:17226937 doi:10.1021/tx600305y
- ↑ Board PG, Coggan M, Cappello J, Zhou H, Oakley AJ, Anders MW. S-(4-Nitrophenacyl)glutathione is a specific substrate for glutathione transferase omega 1-1. Anal Biochem. 2008 Mar 1;374(1):25-30. Epub 2007 Sep 29. PMID:18028863 doi:10.1016/j.ab.2007.09.029
- ↑ Zhou H, Brock J, Casarotto MG, Oakley AJ, Board PG. Novel folding and stability defects cause a deficiency of human glutathione transferase omega 1. J Biol Chem. 2011 Feb 11;286(6):4271-9. Epub 2010 Nov 24. PMID:21106529 doi:10.1074/jbc.M110.197822
- ↑ Zhou H, Brock J, Liu D, Board PG, Oakley AJ. Structural Insights into the Dehydroascorbate Reductase Activity of Human Omega-Class Glutathione Transferases. J Mol Biol. 2012 Apr 18. PMID:22522127 doi:10.1016/j.jmb.2012.04.014
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