3vln

Human Glutathione Transferase O1-1 C32S Mutant in Complex with Ascorbic Acid

spinqualitylabelsall models 3vln, resolution 1.70Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D 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. Method: X-ray diffraction, Resolution 1.7Å Ligands: ACT, ASC, EDO, GOL, SO4 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT 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. 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 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Glutathione S-transferase 3D structures

Proteopedia Page Contributors and Editors (what is this?)

OCA