Database of articles cited by EMDB/PDB/SASBDB data

Keywords
Structure methods	All X-ray diffraction NMR electron microscopy small angle scattering neutron diffraction fiber diffraction powder diffraction infrared spectroscopy EPR fluorescence transfer theoretical model Hybrid
Author
Journal
IF	>30 >20 >10 >5 all

Title	Structures of the Sec61 complex engaged in nascent peptide translocation or membrane insertion.
Journal, issue, pages	Nature, Vol. 506, Issue 7486, Page 107-110, Year 2014
Publish date	Feb 6, 2014
Authors	Marko Gogala / Thomas Becker / Birgitta Beatrix / Jean-Paul Armache / Clara Barrio-Garcia / Otto Berninghausen / Roland Beckmann /
PubMed Abstract	The biogenesis of secretory as well as transmembrane proteins requires the activity of the universally conserved protein-conducting channel (PCC), the Sec61 complex (SecY complex in bacteria). In ...The biogenesis of secretory as well as transmembrane proteins requires the activity of the universally conserved protein-conducting channel (PCC), the Sec61 complex (SecY complex in bacteria). In eukaryotic cells the PCC is located in the membrane of the endoplasmic reticulum where it can bind to translating ribosomes for co-translational protein transport. The Sec complex consists of three subunits (Sec61α, β and γ) and provides an aqueous environment for the translocation of hydrophilic peptides as well as a lateral opening in the Sec61α subunit that has been proposed to act as a gate for the membrane partitioning of hydrophobic domains. A plug helix and a so-called pore ring are believed to seal the PCC against ion flow and are proposed to rearrange for accommodation of translocating peptides. Several crystal and cryo-electron microscopy structures revealed different conformations of closed and partially open Sec61 and SecY complexes. However, in none of these samples has the translocation state been unambiguously defined biochemically. Here we present cryo-electron microscopy structures of ribosome-bound Sec61 complexes engaged in translocation or membrane insertion of nascent peptides. Our data show that a hydrophilic peptide can translocate through the Sec complex with an essentially closed lateral gate and an only slightly rearranged central channel. Membrane insertion of a hydrophobic domain seems to occur with the Sec complex opening the proposed lateral gate while rearranging the plug to maintain an ion permeability barrier. Taken together, we provide a structural model for the basic activities of the Sec61 complex as a protein-conducting channel.
External links	Nature / PubMed:24499919
Methods	EM (single particle)
Resolution	5.5 - 7.8 Å
Structure data	2510 4cg7 EMDB-2510, PDB-4cg7: Cryo-EM of the Sec61-complex bound to the idle 80S ribosome Method: EM (single particle) / Resolution: 6.9 Å 2511 4cg5 EMDB-2511: Cryo-EM of the Sec61-complex bound to an 80S-RNC engaged with a translocating LepT chain PDB-4cg5: Cryo-EM of the Sec61-complex bound to the 80S ribosome translating a secretory substrate Method: EM (single particle) / Resolution: 7.4 Å 2512 4cg6 EMDB-2512: Cryo-EM of the Sec61-complex bound to an 80S-RNC engaged with an membrane-inserting LepM chain PDB-4cg6: Cryo-em of the Sec61-complex bound to the 80s ribosome translating a membrane-inserting substrate Method: EM (single particle) / Resolution: 7.8 Å PDB-4v7e: Model of the small subunit RNA based on a 5.5 A cryo-EM map of Triticum aestivum translating 80S ribosome Method: ELECTRON MICROSCOPY / Resolution: 5.5 Å
Source	triticum aestivum (bread wheat) canis lupus familiaris (dog)
Keywords	PROTEIN TRANSPORT / RIBOSOME / CO-TRANSLATIONAL PROTEIN TRANSLOCATION / eukaryotic ribosome / homology modeling / de novo modeling / ribosomal RNA / rRNA / RNA expansion segments