Evidence for an induced-fit mechanism operating in pi class glutathione transferases.Oakley, A.J., Lo Bello, M., Ricci, G., Federici, G., Parker, M.W.
(1998) Biochemistry 37: 9912-9917
- PubMed: 9665696
- DOI: https://doi.org/10.1021/bi980323w
- Primary Citation of Related Structures:
- PubMed Abstract:
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.
The Ian Potter Foundation Protein Crystallography Laboratory, St. Vincent's Institute of Medical Research, Fitzroy, Victoria, Australia.