複合体: Complex of translationally-stalled ribosome and membrane-embedded YidC insertase
機能・相同性
機能・相同性情報
protein insertion into membrane from inner side / membrane insertase activity / cell envelope Sec protein transport complex / protein transport by the Sec complex / protein insertion into membrane / protein transport / protein folding / protein-containing complex assembly / membrane / plasma membrane 類似検索 - 分子機能
ジャーナル: Cell Rep / 年: 2016 タイトル: Structural Dynamics of the YidC:Ribosome Complex during Membrane Protein Biogenesis. 著者: Alexej Kedrov / Stephan Wickles / Alvaro H Crevenna / Eli O van der Sluis / Robert Buschauer / Otto Berninghausen / Don C Lamb / Roland Beckmann / 要旨: Members of the YidC/Oxa1/Alb3 family universally facilitate membrane protein biogenesis, via mechanisms that have thus far remained unclear. Here, we investigated two crucial functional aspects: the ...Members of the YidC/Oxa1/Alb3 family universally facilitate membrane protein biogenesis, via mechanisms that have thus far remained unclear. Here, we investigated two crucial functional aspects: the interaction of YidC with ribosome:nascent chain complexes (RNCs) and the structural dynamics of RNC-bound YidC in nanodiscs. We observed that a fully exposed nascent transmembrane domain (TMD) is required for high-affinity YidC:RNC interactions, while weaker binding may already occur at earlier stages of translation. YidC efficiently catalyzed the membrane insertion of nascent TMDs in both fluid and gel phase membranes. Cryo-electron microscopy and fluorescence analysis revealed a conformational change in YidC upon nascent chain insertion: the essential TMDs 2 and 3 of YidC were tilted, while the amphipathic helix EH1 relocated into the hydrophobic core of the membrane. We suggest that EH1 serves as a mechanical lever, facilitating a coordinated movement of YidC TMDs to trigger the release of nascent chains into the membrane.