2FH5

The Structure of the Mammalian SRP Receptor

2FH5 の概要

• エントリーDOI: 10.2210/pdb2fh5/pdb
• 分子名称: Signal recognition particle receptor alpha subunit, Signal recognition particle receptor beta subunit, MAGNESIUM ION, ... (5 entities in total)
• 機能のキーワード: endomembrane targeting, gtpase, gap, longin domain, sedl, signal recognition particle receptor, transport protein
• 由来する生物種: Homo sapiens (human); 詳細
• 細胞内の位置: Endoplasmic reticulum membrane; Peripheral membrane protein: P08240; Endoplasmic reticulum membrane; Single-pass membrane protein (By similarity): P47758
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 45413.98

構造登録者

Schlenker, O.,Wild, K.,Sinning, I. (登録日: 2005-12-23, 公開日: 2006-01-31, 最終更新日: 2024-10-30)

主引用文献

Schlenker, O.,Hendricks, A.,Sinning, I.,Wild, K.
The structure of the mammalian signal recognition particle (SRP) receptor as prototype for the interaction of small GTPases with Longin domains.
J.Biol.Chem., 281:8898-8906, 2006

PubMed Abstract: The eukaryotic signal recognition particle (SRP) and its receptor (SR) play a central role in co-translational targeting of secretory and membrane proteins to the endoplasmic reticulum. The SR is a heterodimeric complex assembled by the two GTPases SRalpha and SRbeta, which is membrane-anchored. Here we present the 2.45-A structure of mammalian SRbeta in its Mg2+ GTP-bound state in complex with the minimal binding domain of SRalpha termed SRX. SRbeta is a member of the Ras-GTPase superfamily closely related to Arf and Sar1, while SRX belongs to the SNARE-like superfamily with a fold also known as longin domain. SRX binds to the P loop and the switch regions of SRbeta-GTP. The binding mode and structural similarity with other GTPase-effector complexes suggests a co-GAP (GTPase-activating protein) function for SRX. Comparison with the homologous yeast structure and other longin domains reveals a conserved adjustable hydrophobic surface within SRX which is of central importance for the SRbeta-GTP:SRX interface. A helix swap in SRX results in the formation of a dimer in the crystal structure. Based on structural conservation we present the SRbeta-GTP:SRX structure as a prototype for conserved interactions in a variety of GTPase regulated targeting events occurring at endomembranes.

PubMed: 16439358
DOI: 10.1074/jbc.M512415200

実験手法

X-RAY DIFFRACTION (2.45 Å)