2CJW

Crystal structure of the small GTPase Gem (GemDNDCaM) in complex to Mg.GDP

2CJW の概要

• エントリーDOI: 10.2210/pdb2cjw/pdb
• 関連するPDBエントリー: 2HT6
• 分子名称: GTP-BINDING PROTEIN GEM, GUANOSINE-5'-DIPHOSPHATE, MAGNESIUM ION, ... (5 entities in total)
• 機能のキーワード: g-protein, nucleotide-binding, gtp-binding, small gtpase, conformational change, cysteine-modified, g-protein hydrolase
• 由来する生物種: HOMO SAPIENS (HUMAN); 詳細
• 細胞内の位置: Cell membrane; Peripheral membrane protein; Cytoplasmic side: P55040 P55040
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 45798.82

構造登録者

Splingard, A.,Menetrey, J.,Perderiset, M.,Cicolari, J.,Hamoudi, F.,Cabanie, L.,El Marjou, A.,Wells, A.,Houdusse, A.,de Gunzburg, J. (登録日: 2006-04-09, 公開日: 2006-11-09, 最終更新日: 2024-10-16)

主引用文献

Splingard, A.,Menetrey, J.,Perderiset, M.,Cicolari, J.,Regazzoni, K.,Hamoudi, F.,Cabanie, L.,El Marjou, A.,Wells, A.,Houdusse, A.,De Gunzburg, J.
Biochemical and Structural Characterization of the Gem Gtpase.
J.Biol.Chem., 282:1905-, 2007

PubMed Abstract: RGK proteins, encompassing Rad, Gem, Rem1, and Rem2, constitute an intriguing branch of the Ras superfamily; their expression is regulated at the transcription level, they exhibit atypical nucleotide binding motifs, and they carry both large N- and C-terminal extensions. Biochemical and structural studies are required to better understand how such proteins function. Here, we report the first structure for a RGK protein: the crystal structure of a truncated form of the human Gem protein (G domain plus the first part of the C-terminal extension) in complex with Mg.GDP at 2.1 A resolution. It reveals that the G-domain fold and Mg.GDP binding site of Gem are similar to those found for other Ras family GTPases. The first part of the C-terminal extension adopts an alpha-helical conformation that extends along the alpha5 helix and interacts with the tip of the interswitch. Biochemical studies show that the affinities of Gem for GDP and GTP are considerably lower (micromolar range) compared with H-Ras, independent of the presence or absence of N- and C-terminal extensions, whereas its GTPase activity is higher than that of H-Ras and regulated by both extensions. We show how the bulky DXWEX motif, characteristic of the switch II of RGK proteins, affects the conformation of switch I and the phosphate-binding site. Altogether, our data reveal that Gem is a bona fide GTPase that exhibits striking structural and biochemical features that should impact its regulation and cellular activities.

PubMed: 17107948
DOI: 10.1074/JBC.M604363200

実験手法

X-RAY DIFFRACTION (2.1 Å)