The structural basis for the transition from Ras-GTP to Ras-GDP.

ABSTRACT: The conformational changes in Ras that accompany the hydrolysis of GTP are critical to its function as a molecular switch in signaling pathways. Understanding how GTP is hydrolyzed by revealing the sequence of intermediary structures in the reaction is essential for understanding Ras signaling. Until now, no structure of an intermediate in GTP hydrolysis has been experimentally determined for Ras alone. We have solved the crystal structure of the Ala-59 to Gly mutant of Ras, (RasA59G), bound to guanosine 5'-imidotriphosphate or GDP to 1.7-A resolution. In the guanosine 5'-imidotriphosphate-bound form, this mutant adopts a conformation that is intermediate between the GTP- and GDP-bound forms of wild-type Ras and that is similar to what has been predicted by molecular dynamics simulation [M

SUBMITTER: Hall BE 

PROVIDER: S-EPMC129411 | biostudies-literature | 2002 Sep

REPOSITORIES: biostudies-literature