Format

Send to

Choose Destination
See comment in PubMed Commons below
Nat Struct Mol Biol. 2011 May;18(5):614-21. doi: 10.1038/nsmb.2026. Epub 2011 Apr 17.

Cryo-EM structure of the ribosome-SecYE complex in the membrane environment.

Author information

1
Gene Center, Department for Biochemistry, University of Munich, Munich, Germany.

Abstract

The ubiquitous SecY-Sec61 complex translocates nascent secretory proteins across cellular membranes and integrates membrane proteins into lipid bilayers. Several structures of mostly detergent-solubilized Sec complexes have been reported. Here we present a single-particle cryo-EM structure of the SecYEG complex in a membrane environment, bound to a translating ribosome, at subnanometer resolution. Using the SecYEG complex reconstituted in a so-called Nanodisc, we could trace the nascent polypeptide chain from the peptidyltransferase center into the membrane. The reconstruction allowed for the identification of ribosome-lipid interactions. The rRNA helix 59 (H59) directly contacts the lipid surface and appears to modulate the membrane in immediate vicinity to the proposed lateral gate of the protein-conducting channel (PCC). On the basis of our map and molecular dynamics simulations, we present a model of a signal anchor-gated PCC in the membrane.

PMID:
21499241
PMCID:
PMC3412285
DOI:
10.1038/nsmb.2026
[Indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Nature Publishing Group Icon for PubMed Central
    Loading ...
    Support Center