5CK4

Signal recognition particle receptor SRb-GDP from Chaetomium thermophilum

5CK4 の概要

• エントリーDOI: 10.2210/pdb5ck4/pdb
• 分子名称: Putative signal recognition particle protein, GUANOSINE-5'-DIPHOSPHATE (3 entities in total)
• 機能のキーワード: arf-like gtpase, protein translocation, signaling protein
• 由来する生物種: Chaetomium thermophilum
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 69762.40

構造登録者

Jadhav, B.R.,Sinning, I.,Wild, K. (登録日: 2015-07-15, 公開日: 2015-09-09, 最終更新日: 2024-05-08)

主引用文献

Jadhav, B.,Wild, K.,Pool, M.R.,Sinning, I.
Structure and Switch Cycle of SR beta as Ancestral Eukaryotic GTPase Associated with Secretory Membranes.
Structure, 23:1838-1847, 2015

PubMed Abstract: G proteins of the Ras-family of small GTPases trace the evolution of eukaryotes. The earliest branching involves the closely related Arf, Sar1, and SRβ GTPases associated with secretory membranes. SRβ is an integral membrane component of the signal recognition particle (SRP) receptor that targets ribosome-nascent chain complexes to the ER. How SRβ integrates into the regulation of SRP-dependent membrane protein biogenesis is not known. Here we show that SRβ-GTP interacts with ribosomes only in presence of SRα and present crystal structures of SRβ in complex with the SRX domain of SRα in the GTP-bound state at 3.2 Å, and of GDP- and GDP · Mg(2+)-bound SRβ at 1.9 Å and 2.4 Å, respectively. We define the GTPase switch cycle of SRβ and identify specific differences to the Arf and Sar1 families with implications for GTPase regulation. Our data allow a better integration of SRβ into the scheme of protein targeting.

PubMed: 26299945
DOI: 10.1016/j.str.2015.07.010

実験手法

X-RAY DIFFRACTION (1.89 Å)