Interaction mapping of the Sec61 translocon identifies two Sec61α regions interacting with hydrophobic segments in translocating chains.

ABSTRACT: Many proteins in organelles of the secretory pathway, as well as secretory proteins, are translocated across and inserted into the endoplasmic reticulum membrane by the Sec61 translocon, a protein-conducting channel. The channel consists of 10 transmembrane (TM) segments of the Sec61α subunit and possesses an opening between TM2b and TM7, termed the lateral gate. Structural and biochemical analyses of complexes of Sec61 and its ortholog SecY have revealed that the lateral gate is the exit for signal sequences and TM segments of translocating polypeptides to the lipid bilayer and also involved in the recognition of such hydrophobic sequences. Moreover, even marginally hydrophobic (mH) segments insufficient for membrane integration can be transiently stalled in surrounding Sec61α regions and

SUBMITTER: Kida Y 

PROVIDER: S-EPMC6222115 | biostudies-literature | 2018 Nov

REPOSITORIES: biostudies-literature