AFM observation of protein translocation mediated by one unit of SecYEG-SecA complex
Abstract Protein translocation across cellular membranes is an essential and nano-scale dynamic process. In the bacterial cytoplasmic membrane, the core proteins in this process are a membrane protein complex, SecYEG, corresponding to the eukaryotic Sec61 complex, and a cytoplasmic protein, SecA ATP...
Saved in:
| Main Authors: | , , , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Nature Portfolio
2025-01-01
|
| Series: | Nature Communications |
| Online Access: | https://doi.org/10.1038/s41467-024-54875-x |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | Abstract Protein translocation across cellular membranes is an essential and nano-scale dynamic process. In the bacterial cytoplasmic membrane, the core proteins in this process are a membrane protein complex, SecYEG, corresponding to the eukaryotic Sec61 complex, and a cytoplasmic protein, SecA ATPase. Despite more than three decades of extensive research on Sec proteins, from genetic experiments to cutting-edge single-molecule analyses, no study has visually demonstrated protein translocation. Here, we visualize the translocation, via one unit of a SecYEG-SecA-embedded nanodisc, of an unfolded substrate protein by high-speed atomic force microscopy (HS-AFM). Additionally, the uniform unidirectional distribution of nanodiscs on a mica substrate enables the HS-AFM image data analysis, revealing dynamic structural changes in the polypeptide-crosslinking domain of SecA between wide-open and closed states depending on nucleotides. The nanodisc-AFM approach will allow us to execute detailed analyses of Sec proteins as well as visualize nano-scale events of other membrane proteins. |
|---|---|
| ISSN: | 2041-1723 |