Abstract
The YidC/Oxa1/Alb3 family of membrane proteins facilitates the insertion and assembly of membrane proteins in bacteria, mitochondria, and chloroplasts. Here we present the structures of both Escherichia coli YidC and Saccharomyces cerevisiae Oxa1 bound to E. coli ribosome nascent chain complexes determined by cryo-electron microscopy. Dimers of YidC and Oxa1 are localized above the exit of the ribosomal tunnel. Crosslinking experiments show that the ribosome specifically stabilizes the dimeric state. Functionally important and conserved transmembrane helices of YidC and Oxa1 were localized at the dimer interface by cysteine crosslinking. Both Oxa1 and YidC dimers contact the ribosome at ribosomal protein L23 and conserved rRNA helices 59 and 24, similarly to what was observed for the nonhomologous SecYEG translocon. We suggest that dimers of the YidC and Oxa1 proteins form insertion pores and share a common overall architecture with the SecY monomer.
Original language | English |
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Pages (from-to) | 344 - 353 |
Number of pages | 10 |
Journal | Molecular Cell |
Volume | 34 |
Issue number | 3 |
DOIs | |
Publication status | Published - 15 May 2009 |
Bibliographical note
Other: Front cover graphic relates to articleResearch Groups and Themes
- Bristol BioDesign Institute
Keywords
- synthetic biology
- Electron Transport Complex IV
- Ribosomes
- Bacterial Proteins
- Escherichia coli Proteins
- Nuclear Proteins
- Mitochondrial Proteins
- Protein Binding
- Protein Biosynthesis
- Cysteine
- Multiprotein Complexes
- Models, Molecular
- Protein Structure, Quaternary
- Dimerization
- Membrane Transport Proteins
- Oxidation-Reduction