Structure-function studies of the G-domain from human gem, a novel small G-protein.
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.
Opatowsky
Yarden
Y
Department of Biochemistry, Daniella Rich Institute for Structural Biology, Tel Aviv University, Ramat Aviv 69978, Israel.
Sasson
Yehezkel
Y
Shaked
Isabella
I
Ward
Yvona
Y
Chomsky-Hecht
Orna
O
Litvak
Yael
Y
Selinger
Zvi
Z
Kelly
Kathleen
K
Hirsch
Joel A
JA
D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D019556:COS Cells; D002522:Chlorocebus aethiops; D018360:Crystallography, X-Ray; D006153:Guanosine Diphosphate / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D020559:Monomeric GTP-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D055672:Static Electricity; D054460:rho-Associated Kinases
D047908:Intracellular Signaling Peptides and Proteins; D011994:Recombinant Proteins; D006153:Guanosine Diphosphate; D006160:Guanosine Triphosphate; D017346:Protein Serine-Threonine Kinases; D054460:rho-Associated Kinases; C490245:GEM protein, human; D020559:Monomeric GTP-Binding Proteins