Publication Date:
2009-11-26
Description:
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.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2920595/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉 〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2920595/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Becker, Thomas -- Bhushan, Shashi -- Jarasch, Alexander -- Armache, Jean-Paul -- Funes, Soledad -- Jossinet, Fabrice -- Gumbart, James -- Mielke, Thorsten -- Berninghausen, Otto -- Schulten, Klaus -- Westhof, Eric -- Gilmore, Reid -- Mandon, Elisabet C -- Beckmann, Roland -- GM35687/GM/NIGMS NIH HHS/ -- P41 RR005969/RR/NCRR NIH HHS/ -- P41 RR005969-19/RR/NCRR NIH HHS/ -- P41-RR05969/RR/NCRR NIH HHS/ -- R01-GM067887/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2009 Dec 4;326(5958):1369-73. doi: 10.1126/science.1178535. Epub 2009 Oct 29.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Gene Center Munich and Center for Integrated Protein Science, Department of Chemistry and Biochemistry, Ludwig-Maximilians-Universitat Munchen, Feodor-Lynen-Strasse 25, 81377 Munich, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19933108" target="_blank"〉PubMed〈/a〉
Keywords:
Animals
;
Binding Sites
;
Cryoelectron Microscopy
;
Dogs
;
Image Processing, Computer-Assisted
;
Membrane Proteins/*chemistry/*metabolism/ultrastructure
;
Models, Molecular
;
*Protein Biosynthesis
;
Protein Conformation
;
Protein Multimerization
;
Protein Structure, Secondary
;
*Protein Transport
;
Proteins/chemistry/*metabolism/ultrastructure
;
Ribosomes/*metabolism/ultrastructure
;
Saccharomyces cerevisiae Proteins/*chemistry/*metabolism/ultrastructure
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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