Three-dimensional structures of the apo form of human pi class glutathione transferase have been determined by X-ray crystallography. The structures suggest the enzyme recognizes its substrate, glutathione, by an induced-fit mechanism. Compared to complexed forms of the enzyme, the environment around the catalytic residue, Tyr 7, remains unchanged in the apoenzyme. This observation supports the view that Tyr 7 does not act as a general base in the reaction mechanism. The observed cooperativity of the dimeric enzyme may be due to the movements of a helix that forms one wall of the active site and, in particular, to movements of a tyrosine residue that is located in the subunit interface.
Evidence for an induced-fit mechanism operating in pi class glutathione transferases.,Oakley AJ, Lo Bello M, Ricci G, Federici G, Parker MW Biochemistry. 1998 Jul 14;37(28):9912-7. PMID:9665696
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
↑ Oakley AJ, Lo Bello M, Ricci G, Federici G, Parker MW. Evidence for an induced-fit mechanism operating in pi class glutathione transferases. Biochemistry. 1998 Jul 14;37(28):9912-7. PMID:9665696 doi:10.1021/bi980323w