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-Structure paper
Title | Structure of monomeric yeast and mammalian Sec61 complexes interacting with the translating ribosome. |
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Journal, issue, pages | Science, Vol. 326, Issue 5958, Page 1369-1373, Year 2009 |
Publish date | Dec 4, 2009 |
Authors | Thomas Becker / Shashi Bhushan / Alexander Jarasch / Jean-Paul Armache / Soledad Funes / Fabrice Jossinet / James Gumbart / Thorsten Mielke / Otto Berninghausen / Klaus Schulten / Eric Westhof / Reid Gilmore / Elisabet C Mandon / Roland Beckmann / |
PubMed Abstract | The trimeric Sec61/SecY complex is a protein-conducting channel (PCC) for secretory and membrane proteins. Although Sec complexes can form oligomers, it has been suggested that a single copy may ...The trimeric Sec61/SecY complex is a protein-conducting channel (PCC) for secretory and membrane proteins. Although Sec complexes can form oligomers, it has been suggested that a single copy may serve as an active PCC. We determined subnanometer-resolution cryo-electron microscopy structures of eukaryotic ribosome-Sec61 complexes. In combination with biochemical data, we found that in both idle and active states, the Sec complex is not oligomeric and interacts mainly via two cytoplasmic loops with the universal ribosomal adaptor site. In the active state, the ribosomal tunnel and a central pore of the monomeric PCC were occupied by the nascent chain, contacting loop 6 of the Sec complex. This provides a structural basis for the activity of a solitary Sec complex in cotranslational protein translocation. |
External links | Science / PubMed:19933108 / PubMed Central |
Methods | EM (single particle) |
Resolution | 6.1 - 8.9 Å |
Structure data | EMDB-1651: EMDB-1652: Cryo-EM structure of the mammalian Sec61 complex bound to the actively translating wheat germ 80S ribosome EMDB-1667: Cryo-EM structure of the active yeast Ssh1 complex bound to the programmed yeast 80S ribosome bearing a P-site tRNA EMDB-1668: |
Source |
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Keywords | RIBOSOME / RIBOSOMAL PROTEIN / RIBONUCLEOPROTEIN / TRANSMEMBRANE / PHOSPHOPROTEIN / SIGNAL SEQUENCE / MEMBRANE / TRANSPORT / RNA-BINDING / RRNA-BINDING / TRANSLOCATION / PROTEIN CONDUCTING CHANNEL / PROTEIN EXIT TUNNEL / ENDOPLASMIC RETICULUM / COTRANSLATIONAL PROTEIN TRANSLOCATION / ISOPEPTIDE BOND / PROTEIN TRANSPORT |