1G17

CRYSTAL STRUCTURE OF SEC4-GUANOSINE-5'-(BETA,GAMMA)-IMIDOTRIPHOSPHATE

1G17 の概要

• エントリーDOI: 10.2210/pdb1g17/pdb
• 関連するPDBエントリー: 1G16
• 分子名称: RAS-RELATED PROTEIN SEC4, MAGNESIUM ION, PHOSPHOAMINOPHOSPHONIC ACID-GUANYLATE ESTER, ... (4 entities in total)
• 機能のキーワード: g protein rab, signaling protein, endocytosis-exocytosis complex, endocytosis/exocytosis
• 由来する生物種: Saccharomyces cerevisiae (baker's yeast)
• 細胞内の位置: Cytoplasmic vesicle, secretory vesicle membrane; Lipid-anchor; Cytoplasmic side: P07560
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 39422.74

構造登録者

Stroupe, C.,Brunger, A.T. (登録日: 2000-10-10, 公開日: 2000-12-11, 最終更新日: 2024-02-07)

主引用文献

Stroupe, C.,Brunger, A.T.
Crystal structures of a Rab protein in its inactive and active conformations.
J.Mol.Biol., 304:585-598, 2000

PubMed Abstract: We have determined crystal structures of Sec4, a member of the Rab family in the G protein superfamily, in two states: bound to GDP, and to a non-hydrolyzable GTP analog, guanosine-5'-(beta, gamma)-imidotriphosphate (GppNHp). This represents the first structure of a Rab protein bound to GDP. Sec4 in both states grossly resembles other G proteins bound to GDP and GppNHp. In Sec4-GppNHp, structural features common to active Rab proteins are observed. In Sec4-GDP, the switch I region is highly disordered and displaced relative to the switch I region of Ras-GDP. In two of the four molecules of Sec4-GDP in the asymmetric unit of the Sec4-GDP crystals, the switch II region adopts a conformation similar to that seen in the structure of the small G protein Ran bound to GDP. This allows residues threonine 76, glutamate 80, and arginine 81 of Sec4 to make contacts with other conserved residues and water molecules important for nucleotide binding. In the other two molecules in the asymmetric unit, these interactions do not take place. This structural variability in both the switch I and switch II regions of GDP-bound Sec4 provides a possible explanation for the high off-rate of GDP bound to Sec4, and suggests a mechanism for regulation of the GTPase cycle of Rab proteins by GDI proteins.

PubMed: 11099382
DOI: 10.1006/jmbi.2000.4236

実験手法

X-RAY DIFFRACTION (2 Å)