GLUTATHIONE S-TRANSFERASE FROM SQUID DIGESTIVE GLAND COMPLEXED WITH S-(3-IODOBENZYL)GLUTATHIONE
[GST_OMMSL] High activity toward 1-chloro-2,4-dinitrobenzene. Not very efficient at catalyzing the addition of GSH to enones and epoxides.
Publication Abstract from PubMed
The crystal structure of the sigma class glutathione transferase from squid digestive gland in complex with S-(3-iodobenzyl)glutathione reveals a third binding site for the glutathione conjugate besides the two in the active sites of the dimer. The additional binding site is near the crystallographic two-fold axis between the two alpha 4-turn-alpha 5 motifs. The principal binding interactions with the conjugate include specific electrostatic interactions between the peptide and the two subunits and a hydrophobic cavity found across the two-fold axis that accommodates the 3-iodobenzyl group. Thus, two identical, symmetry-related but mutually exclusive binding modes for the third conjugate are observed. The hydrophobic pocket is about 14 A from the hydroxyl group of Tyr-7 in the active site. This site is a potential transport binding site for hydrophobic molecules or their glutathione conjugates.
Location of a potential transport binding site in a sigma class glutathione transferase by x-ray crystallography.,Ji X, von Rosenvinge EC, Johnson WW, Armstrong RN, Gilliland GL Proc Natl Acad Sci U S A. 1996 Aug 6;93(16):8208-13. PMID:8710848
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.