ジャーナル: Nat Struct Mol Biol / 年: 2013 タイトル: Structural characterization of a eukaryotic chaperone--the ribosome-associated complex. 著者: Christoph Leidig / Gert Bange / Jürgen Kopp / Stefan Amlacher / Ajay Aravind / Stephan Wickles / Gregor Witte / Ed Hurt / Roland Beckmann / Irmgard Sinning / 要旨: Ribosome-associated chaperones act in early folding events during protein synthesis. Structural information is available for prokaryotic chaperones (such as trigger factor), but structural ...Ribosome-associated chaperones act in early folding events during protein synthesis. Structural information is available for prokaryotic chaperones (such as trigger factor), but structural understanding of these processes in eukaryotes lags far behind. Here we present structural analyses of the eukaryotic ribosome-associated complex (RAC) from Saccharomyces cerevisiae and Chaetomium thermophilum, consisting of heat-shock protein 70 (Hsp70) Ssz1 and the Hsp40 Zuo1. RAC is an elongated complex that crouches over the ribosomal tunnel exit and seems to be stabilized in a distinct conformation by expansion segment ES27. A unique α-helical domain in Zuo1 mediates ribosome interaction of RAC near the ribosomal proteins L22e and L31e and ribosomal RNA helix H59. The crystal structure of the Ssz1 ATPase domain bound to ATP-Mg²⁺ explains its catalytic inactivity and suggests that Ssz1 may act before the RAC-associated chaperone Ssb. Our study offers insights into the interplay between RAC, the ER membrane-integrated Hsp40-type protein ERj1 and the signal-recognition particle.
全体 : Ribosome-associated complex (RAC) bound to 80S ribosome
全体
名称: Ribosome-associated complex (RAC) bound to 80S ribosome
要素
試料: Ribosome-associated complex (RAC) bound to 80S ribosome
複合体: 80S ribosome
タンパク質・ペプチド: Ribosome-associated complex
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超分子 #1000: Ribosome-associated complex (RAC) bound to 80S ribosome
超分子
名称: Ribosome-associated complex (RAC) bound to 80S ribosome タイプ: sample / ID: 1000 詳細: Sample was reconstituted from the purified components 集合状態: One RAC binds to one ribosome / Number unique components: 2
分子量
理論値: 3.2 MDa
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超分子 #1: 80S ribosome
超分子
名称: 80S ribosome / タイプ: complex / ID: 1 / 組換発現: No / Ribosome-details: ribosome-eukaryote: ALL