Oakley A J, Lo Bello M, Ricci G, Federici G, Parker M W
The Ian Potter Foundation Protein Crystallography Laboratory, St. Vincent's Institute of Medical Research, Fitzroy, Victoria, Australia.
Biochemistry. 1998 Jul 14;37(28):9912-7. doi: 10.1021/bi980323w.
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.
通过X射线晶体学确定了人π类谷胱甘肽转移酶脱辅基形式的三维结构。这些结构表明该酶通过诱导契合机制识别其底物谷胱甘肽。与该酶的复合形式相比，催化残基Tyr 7周围的环境在脱辅基酶中保持不变。这一观察结果支持了Tyr 7在反应机制中不作为通用碱的观点。观察到的二聚体酶的协同性可能是由于形成活性位点一侧壁的螺旋的移动，特别是位于亚基界面的一个酪氨酸残基的移动。
