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bioRxiv · 10.1101/179283

Effect of ligands on stability of H-Ras GTPase

Kovrigina, E. A.·O'Connor, C.·Kovrigin, E. L.
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Abstract

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.

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Kovrigina, E. A., O'Connor, C., Kovrigin, E. L.. 2017-08-21. Effect of ligands on stability of H-Ras GTPase. https://doi.org/10.1101/179283

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