Samuel Itskanov / Katie M Kuo / James C Gumbart / Eunyong Park /
PubMed Abstract
Many proteins are transported into the endoplasmic reticulum by the universally conserved Sec61 channel. Post-translational transport requires two additional proteins, Sec62 and Sec63, but their ...Many proteins are transported into the endoplasmic reticulum by the universally conserved Sec61 channel. Post-translational transport requires two additional proteins, Sec62 and Sec63, but their functions are poorly defined. In the present study, we determined cryo-electron microscopy (cryo-EM) structures of several variants of Sec61-Sec62-Sec63 complexes from Saccharomyces cerevisiae and Thermomyces lanuginosus and show that Sec62 and Sec63 induce opening of the Sec61 channel. Without Sec62, the translocation pore of Sec61 remains closed by the plug domain, rendering the channel inactive. We further show that the lateral gate of Sec61 must first be partially opened by interactions between Sec61 and Sec63 in cytosolic and luminal domains, a simultaneous disruption of which completely closes the channel. The structures and molecular dynamics simulations suggest that Sec62 may also prevent lipids from invading the channel through the open lateral gate. Our study shows how Sec63 and Sec62 work together in a hierarchical manner to activate Sec61 for post-translational protein translocation.
EMDB-22770, PDB-7kah: Cryo-EM structure of the Sec complex from S. cerevisiae, wild-type, class without Sec62 Method: EM (single particle) / Resolution: 3.1 Å
EMDB-22771, PDB-7kai: Cryo-EM structure of the Sec complex from S. cerevisiae, wild-type, class with Sec62, conformation 1 (C1) Method: EM (single particle) / Resolution: 3.2 Å
EMDB-22772, PDB-7kaj: Cryo-EM structure of the Sec complex from S. cerevisiae, wild-type, class with Sec62, conformation 2 (C2) Method: EM (single particle) / Resolution: 3.1 Å
EMDB-22773, PDB-7kak: Cryo-EM structure of the Sec complex from T. lanuginosus, wild-type, class without Sec62 Method: EM (single particle) / Resolution: 3.9 Å
EMDB-22774, PDB-7kal: Cryo-EM structure of the Sec complex from T. lanuginosus, wild-type, class with Sec62, plug-open conformation Method: EM (single particle) / Resolution: 4.0 Å
EMDB-22775, PDB-7kam: Cryo-EM structure of the Sec complex from T. lanuginosus, wild-type, class with Sec62, plug-closed conformation Method: EM (single particle) / Resolution: 3.8 Å
EMDB-22776: Cryo-EM structure of the Sec complex from T. lanuginosus lacking Sec62 PDB-7kan: Cryo-EM structure of the Sec complex from T. lanuginosus, Sec62-lacking mutant (Delta Sec62) Method: EM (single particle) / Resolution: 3.7 Å
EMDB-22777: Cryo-EM structure of the Sec complex from T. lanuginosus, Sec62 anchor domain mutant (delta anchor) Method: EM (single particle) / Resolution: 4.4 Å
EMDB-22778, PDB-7kao: Cryo-EM structure of the Sec complex from S. cerevisiae, Sec61 pore mutant, class without Sec62 Method: EM (single particle) / Resolution: 4.0 Å
EMDB-22779, PDB-7kap: Cryo-EM structure of the Sec complex from S. cerevisiae, Sec61 pore mutant, class with Sec62, conformation 1 (C1) Method: EM (single particle) / Resolution: 4.1 Å
EMDB-22780, PDB-7kaq: Cryo-EM structure of the Sec complex from S. cerevisiae, Sec61 pore mutant, class with Sec62, conformation 2 (C2) Method: EM (single particle) / Resolution: 4.0 Å
EMDB-22781, PDB-7kar: Cryo-EM structure of the Sec complex from S. cerevisiae, Sec63 FN3 mutant, class without Sec62 Method: EM (single particle) / Resolution: 4.0 Å
EMDB-22782, PDB-7kas: Cryo-EM structure of the Sec complex from S. cerevisiae, Sec63 FN3 mutant, class with Sec62 Method: EM (single particle) / Resolution: 3.9 Å
EMDB-22783, PDB-7kat: Cryo-EM structure of the Sec complex from S. cerevisiae, Sec61 pore ring and Sec63 FN3 double mutant, class without Sec62 Method: EM (single particle) / Resolution: 4.4 Å
EMDB-22784, PDB-7kau: Cryo-EM structure of the Sec complex from S. cerevisiae, Sec61 pore ring and Sec63 FN3 double mutant, class with Sec62 Method: EM (single particle) / Resolution: 4.0 Å
EMDB-22785: Cryo-EM structure of the Sec complex from S. cerevisiae, wild-type, consensus map Method: EM (single particle) / Resolution: 3.0 Å
EMDB-22786: Cryo-EM structure of the Sec complex from T. lanuginosus, wild-type, consensus map of classes with Sec62 Method: EM (single particle) / Resolution: 3.75 Å
EMDB-22787, PDB-7kb5: Cryo-EM structure of the Sec complex from yeast, Sec63 FN3 and residues 210-216 mutated Method: EM (single particle) / Resolution: 3.8 Å
In the structure databanks used in Yorodumi, some data are registered as the other names, "COVID-19 virus" and "2019-nCoV". Here are the details of the virus and the list of structure data.
Jan 31, 2019. EMDB accession codes are about to change! (news from PDBe EMDB page)
EMDB accession codes are about to change! (news from PDBe EMDB page)
The allocation of 4 digits for EMDB accession codes will soon come to an end. Whilst these codes will remain in use, new EMDB accession codes will include an additional digit and will expand incrementally as the available range of codes is exhausted. The current 4-digit format prefixed with “EMD-” (i.e. EMD-XXXX) will advance to a 5-digit format (i.e. EMD-XXXXX), and so on. It is currently estimated that the 4-digit codes will be depleted around Spring 2019, at which point the 5-digit format will come into force.
The EM Navigator/Yorodumi systems omit the EMD- prefix.
Related info.:Q: What is EMD? / ID/Accession-code notation in Yorodumi/EM Navigator