1PGT: Crystal Structure Of Human Glutathione S-Transferase P1- 1[v104] Complexed With S-Hexylglutathione

Citation:
Abstract
Complex structures of a naturally occurring variant of human class pi glutathione S-transferase 1-1 (hGSTP1-1) with either S-hexylglutathione or (9R,10R)-9-(S-glutathionyl)-10-hydroxy-9, 10-dihydrophenanthrene [(9R,10R)-GSPhen] have been determined at resolutions of 1.8 and 1.9 A, respectively. The crystal structures reveal that the xenobiotic substrate-binding site (H-site) is located at a position similar to that observed in class mu GST 1-1 from rat liver (rGSTM1-1). In rGSTM1-1, the H-site is a hydrophobic cavity defined by the side chains of Y6, W7, V9, L12, I111, Y115, F208, and S209. In hGSTP1-1, the cavity is approximately half hydrophobic and half hydrophilic and is defined by the side chains of Y7, F8, V10, R13, V104, Y108, N204, and G205 and five water molecules. A hydrogen bond network connects the five water molecules and the side chains of R13 and N204. V104 is positioned such that the introduction of a methyl group (the result of the V104I mutation) disturbs the H-site water structure and alters the substrate-binding properties of the isozyme. The hydroxyl group of Y7 forms a hydrogen bond (3.2 A) with the sulfur atom of the product. There is a short hydrogen bond (2.5 A) between Y108 (OH) and (9R, 10R)-GSPhen (O5), indicating the hydroxyl group of Y108 as an electrophilic participant in the addition of glutathione to epoxides. An N-(2-hydroxethyl)piperazine-N'-2-ethanesulfonic acid (HEPES) molecule is found in the cavity between beta2 and alphaI. The location and properties of this HEPES-binding site fit a possible non-substrate-binding site that is involved in noncompetitive inhibition of the enzyme.
PDB ID: 1PGTDownload
MMDB ID: 6475
PDB Deposition Date: 1997/2/17
Updated in MMDB: 1998/11
Experimental Method:
x-ray diffraction
Resolution: 1.8  Å
Source Organism:
Similar Structures:
Biological Unit for 1PGT: dimeric; determined by author and by software (PISA)
Molecular Components in 1PGT
Label Count Molecule
Proteins (2 molecules)
2
Glutathione S-transferase(Gene symbol: GSTP1)
Molecule annotation
Chemicals (4 molecules)
1
2
2
2
* Click molecule labels to explore molecular sequence information.

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