9R9P

Yeast 80S with nascent chain in complex with Ssb1-ADP in the S2 state

これはPDB形式変換不可エントリーです。

9R9P の概要

• エントリーDOI: 10.2210/pdb9r9p/pdb
• EMDBエントリー: 53861
• 分子名称: mRNA_Flag-Pgk-1-70, 60S ribosomal protein L3, 60S ribosomal protein L4-A, ... (79 entities in total)
• 機能のキーワード: hsp70, nascent chain, 80s, ssb, ribosome
• 由来する生物種: Saccharomyces cerevisiae (brewer's yeast); 詳細
• タンパク質・核酸の鎖数: 79
• 化学式量合計: 3233746.60

構造登録者

Grundmann, L.,Zhang, Y.,Grishkovskaya, I.,Rospert, S.,Haselbach, D. (登録日: 2025-05-20, 公開日: 2025-12-24, 最終更新日: 2026-03-11)

主引用文献

Zhang, Y.,Grundmann, L.,Vollmar, L.,Schimpf, J.,Hubscher, V.,Areeb, M.,Grishkovskaya, I.,Moddemann, A.,Werner, K.,Hugel, T.,Haselbach, D.,Rospert, S.
The cotranslational cycle of the ribosome-bound Hsp70 homolog Ssb.
Nat Commun, 17:961-961, 2026

PubMed Abstract: Coupling of ribosomal translation with cotranslational protein folding is essential for cellular homeostasis. In eukaryotes, Hsp70 and its J-domain cochaperone, the heterodimeric ribosome-associated complex (RAC), are central to this process; however, mechanistic insights into the coordination of Hsp70 function with translation remain limited. Here, we present two cryo-EM structures of the ribosome-bound yeast Hsp70 Ssb, identifying Rpl25/uL23 as the ribosomal binding site and revealing its interaction with a model nascent chain. Together with detailed biochemical and mutational analyses, these structures enable us to delineate the intricate RAC-dependent cycle, which positions the substrate binding domain of Ssb-ATP close to the tunnel exit to receive nascent chains. This arrangement allows Ssb to undergo substantial conformational changes upon ATP hydrolysis without steric clashes with the ribosome, while the substrate binding domain of Ssb, now anchored by the tightly bound nascent chain, remains close to the tunnel exit.

PubMed: 41545346
DOI: 10.1038/s41467-025-67685-6

実験手法

ELECTRON MICROSCOPY (3 Å)