Download MendeleyStructural Dynamics of the YidC:Ribosome Complex during Membrane Protein Biogenesis.
Kedrov, A., Wickles, S., Crevenna, A.H., van der Sluis, E.O., Buschauer, R., Berninghausen, O., Lamb, D.C., Beckmann, R.(2016) Cell Rep 17: 2943-2954
- PubMed: 27974208
- DOI: https://doi.org/10.1016/j.celrep.2016.11.059
- Primary Citation of Related Structures:
5M5H - PubMed Abstract:
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.
Organizational Affiliation:
Gene Center Munich, Department of Biochemistry, Ludwig-Maximilians-University Munich, Feodor-Lynen-Strasse 25, Munich 81377, Germany. Electronic address: kedrov@genzentrum.lmu.de.
