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Oligomeric rings of the Sec61p complex induced by ligands required for protein translocation

Item Type:Article
Title:Oligomeric rings of the Sec61p complex induced by ligands required for protein translocation
Creators Name:Hanein, D. and Matlack, K.E.S. and Jungnickel, B. and Plath, K. and Kalies, K.U. and Miller, K.R. and Rapoport, T.A. and Akey, C.W.
Abstract:The heterotrimeric Sec61p complex is a major component of the protein-conducting channel of the endoplasmic reticulum (ER) membrane, associating with either ribosomes or the Sec62/63 complex to perform co- and posttranslational transport, respectively. We show by electron microscopy that purified mammalian and yeast Sec61p complexes in detergent form cylindrical oligomers with a diameter of approximately 85 A and a central pore of approximately 20 A. Each oligomer contains 3-4 heterotrimers. Similar ring structures are seen in reconstituted proteoliposomes and native membranes. Oligomer formation by the reconstituted Sec61p complex is stimulated by its association with ribosomes or the Sec62/63p complex. We propose that these cylindrical oligomers represent protein-conducting channels of the ER, formed by ligands specific for co- and posttranslational transport.
Keywords:Biological Models, Biological Transport, Cell Compartmentation, Detergents, Endoplasmic Reticulum, Freeze Fracturing, Fungal Proteins, Heat-Shock Proteins, Image Enhancement, Ion Channel Gating, Ion Channels, Macromolecular Substances, Membrane Proteins, Membrane Transport Proteins, Molecular Weight, Motion, Negative Staining, Particle Size, Protein Binding, Protein Biosynthesis, Protein Conformation, Proteolipids, Ribosomes, Saccharomyces Cerevisiae Proteins, Yeasts, Animals, Dogs
Publisher:Cell Press
Page Range:721-732
Date:15 November 1996
Official Publication:https://doi.org/10.1016/S0092-8674(00)81391-4
PubMed:View item in PubMed

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