RT Journal Article
SR Electronic
T1 Effect of ligands on stability of H-Ras GTPase
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 179283
DO 10.1101/179283
A1 Elizaveta A Kovrigina
A1 Casey O’Connor
A1 Evgenii L Kovrigin
YR 2017
UL http://biorxiv.org/content/early/2017/08/21/179283.abstract
AB The G domain of a small monomeric GTPase Ras contains a nucleotide-binding pocket and a magnesium-binding site essential for the Ras function in cellular signaling. The G domain also has another (allosteric) ion-binding site on the rear surface of the G domain, which function is still unknown. In this paper, we detailed the effect of calcium and magnesium ions on stability of Ras bound to GDP, GTP, and GTP-mimic GppNHp. We revealed that the remote allosteric ion-binding site contributes very significantly to stability of Ras in the GDP-bound conformation, but nearly not at all—when Ras is bound to a GTP mimic. These findings highlight that further studies of the remote ion-binding site are warranted to reveal its role in the Ras function.