Lateral opening of a translocon upon entry of protein suggests the mechanism of insertion into membranes
10.1073/pnas.1012556107
Crossref journal-article
Proceedings of the National Academy of Sciences
Proceedings of the National Academy of Sciences (341)
Abstract

The structure of the protein-translocating channel SecYEβ from Pyrococcus furiosus at 3.1-Å resolution suggests a mechanism for chaperoning transmembrane regions of a protein substrate during its lateral delivery into the lipid bilayer. Cytoplasmic segments of SecY orient the C-terminal α-helical region of another molecule, suggesting a general binding mode and a promiscuous guiding surface capable of accommodating diverse nascent chains at the exit of the ribosomal tunnel. To accommodate this putative nascent chain mimic, the cytoplasmic vestibule widens, and a lateral exit portal is opened throughout its entire length for partition of transmembrane helical segments to the lipid bilayer. In this primed channel, the central plug still occludes the pore while the lateral gate is opened, enabling topological arbitration during early protein insertion. In vivo, a 15 amino acid truncation of the cytoplasmic C-terminal helix of SecY fails to rescue a secY -deficient strain, supporting the essential role of this helix as suggested from the structure.

Bibliography

Egea, P. F., & Stroud, R. M. (2010). Lateral opening of a translocon upon entry of protein suggests the mechanism of insertion into membranes. Proceedings of the National Academy of Sciences, 107(40), 17182–17187.

Authors 2
  1. Pascal F. Egea (first)
  2. Robert M. Stroud (additional)
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Dates
Type When
Created 14 years, 11 months ago (Sept. 21, 2010, 12:37 a.m.)
Deposited 3 years, 2 months ago (June 7, 2022, 3:04 a.m.)
Indexed 1 month, 3 weeks ago (July 2, 2025, 2:34 p.m.)
Issued 14 years, 11 months ago (Sept. 20, 2010)
Published 14 years, 11 months ago (Sept. 20, 2010)
Published Online 14 years, 11 months ago (Sept. 20, 2010)
Published Print 14 years, 10 months ago (Oct. 5, 2010)
Funders 0

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@article{Egea_2010, title={Lateral opening of a translocon upon entry of protein suggests the mechanism of insertion into membranes}, volume={107}, ISSN={1091-6490}, url={http://dx.doi.org/10.1073/pnas.1012556107}, DOI={10.1073/pnas.1012556107}, number={40}, journal={Proceedings of the National Academy of Sciences}, publisher={Proceedings of the National Academy of Sciences}, author={Egea, Pascal F. and Stroud, Robert M.}, year={2010}, month=sep, pages={17182–17187} }