Related Experiment Video
Updated: Jul 26, 2026

Spatio-Temporal Manipulation of Small GTPase Activity at Subcellular Level and on Timescale of Seconds in Living Cells
Published on: March 9, 2012
Time-resolved X-ray crystallographic study of the conformational change in Ha-Ras p21 protein on GTP hydrolysis
I Schlichting1, S C Almo, G Rapp
1Abteilung Biophysik, Max-Planck-Institut für Medizinische Forschung, Heidelberg, FRG.
Abstract:
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.
More Related Videos
Related Concept Videos
GTPases and their Regulation
Large G-proteins, also known...
Rab Proteins
Rab proteins switch between a cytosolic, GDP-bound inactive state and a membrane-anchored, GTP-bound active state. By themselves, Rabs show slow rates of GDP/GTP exchange and GTP hydrolysis. Thus, Rab proteins are considered...
The Ras Gene
Ras is a superfamily...
Rab Cascades
Small GTPases - Ras and Rho
Three regulatory proteins control their activity:
Activation and Inactivation of G Proteins

