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Updated: Jul 19, 2026

A Kinetic Fluorescence-based Ca2+ Mobilization Assay to Identify G Protein-coupled Receptor Agonists, Antagonists, and Allosteric Modulators
Published on: February 20, 2018
Structure-function studies of the G-domain from human gem, a novel small G-protein
Yarden Opatowsky1, Yehezkel Sasson, Isabella Shaked
1Department of Biochemistry, Daniella Rich Institute for Structural Biology, Tel Aviv University, Ramat Aviv 69978, Israel.
Abstract:
Gem, a member of the Rad,Gem/Kir subfamily of small G-proteins, has unique sequence features. We report here the crystallographic structure determination of the Gem G-domain in complex with nucleotide to 2.4 A resolution. Although the basic Ras protein fold is maintained, the Gem switch regions emphatically differ from the Ras paradigm. Our ensuing biochemical characterization indicates that Gem G-domain markedly prefers GDP over GTP. Two known functions of Gem are distinctly affected by spatially separated clusters of mutations.
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