ジャーナル: Elife / 年: 2018 タイトル: The shape of the bacterial ribosome exit tunnel affects cotranslational protein folding. 著者: Renuka Kudva / Pengfei Tian / Fátima Pardo-Avila / Marta Carroni / Robert B Best / Harris D Bernstein / Gunnar von Heijne / 要旨: The ribosome exit tunnel can accommodate small folded proteins, while larger ones fold outside. It remains unclear, however, to what extent the geometry of the tunnel influences protein folding. ...The ribosome exit tunnel can accommodate small folded proteins, while larger ones fold outside. It remains unclear, however, to what extent the geometry of the tunnel influences protein folding. Here, using ribosomes with deletions in loops in proteins uL23 and uL24 that protrude into the tunnel, we investigate how tunnel geometry determines where proteins of different sizes fold. We find that a 29-residue zinc-finger domain normally folding close to the uL23 loop folds deeper in the tunnel in uL23 Δloop ribosomes, while two ~ 100 residue proteins normally folding close to the uL24 loop near the tunnel exit port fold at deeper locations in uL24 Δloop ribosomes, in good agreement with results obtained by coarse-grained molecular dynamics simulations. This supports the idea that cotranslational folding commences once a protein domain reaches a location in the exit tunnel where there is sufficient space to house the folded structure.
全体 : E.coli ribosome with beta-hairpin of uL23 deleted
全体
名称: E.coli ribosome with beta-hairpin of uL23 deleted
要素
複合体: E.coli ribosome with beta-hairpin of uL23 deleted
タンパク質・ペプチド: 50S ribosomal protein L23
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超分子 #1: E.coli ribosome with beta-hairpin of uL23 deleted
超分子
名称: E.coli ribosome with beta-hairpin of uL23 deleted / タイプ: complex / ID: 1 / 親要素: 0 / 含まれる分子: all 詳細: Deposited PDB is of the uL23 with the beta-hairpin loop deleted.
モデルのタイプ: NONE / 詳細: Ab initio done using cryosparc
最終 再構成
使用したクラス数: 1 / 想定した対称性 - 点群: C1 (非対称) / アルゴリズム: BACK PROJECTION / 解像度のタイプ: BY AUTHOR / 解像度: 3.2 Å / 解像度の算出法: FSC 0.143 CUT-OFF / ソフトウェア - 名称: cryoSPARC 詳細: All processing from ab initio to refinement and sharpening performed in cryosparc 使用した粒子像数: 132029
初期 角度割当
タイプ: NOT APPLICABLE
最終 角度割当
タイプ: NOT APPLICABLE
最終 3次元分類
クラス数: 3
FSC曲線 (解像度の算出)
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原子モデル構築 1
精密化
プロトコル: RIGID BODY FIT
得られたモデル
PDB-6fu8: uL23 beta hairpin loop deletion of E.coli ribosome