Schlichting I, Almo S C, Rapp G, Wilson K, Petratos K, Lentfer A, Wittinghofer A, Kabsch W, Pai E F, Petsko G A
Abteilung Biophysik, Max-Planck-Institut für Medizinische Forschung, Heidelberg, FRG.
Nature. 1990 May 24;345(6273):309-15. doi: 10.1038/345309a0.
Crystals of Ha-Ras p21 with caged GTP at the active site have been used to investigate the conformational changes of p21 on GTP hydrolysis. The structure of the short-lived p21.GTP complex was determined by Laue diffraction methods. After GTP hydrolysis, substantial structural changes occur in the parts of the molecule implicated in the interaction with GTPase-activating protein. The trigger for this process seems to be a change in coordination of the active-site Mg2+ ion as a result of loss of the gamma-phosphate of GTP.
活性位点带有笼形鸟苷三磷酸（GTP）的Ha-Ras p21晶体已被用于研究p21在GTP水解时的构象变化。通过劳厄衍射法确定了短暂存在的p21·GTP复合物的结构。GTP水解后，分子中与GTP酶激活蛋白相互作用相关的部分发生了显著的结构变化。这一过程的触发因素似乎是由于GTP的γ-磷酸基团丢失导致活性位点镁离子配位的改变。
