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Published on: March 16, 2022
The bacterial Sec-translocase: structure and mechanism
Jelger A Lycklama A Nijeholt1, Arnold J M Driessen
1Department of Molecular Microbiology, Groningen Biomolecular Science and Biotechnology Institute, University of Groningen, Nijenborgh 7, Groningen 9747 AG, The Netherlands. a.j.m.driessen@rug.nl
Summary
Bacterial protein translocation across the cytoplasmic membrane relies on the SecYEG translocase and SecA motor. Advances in understanding the structural and biochemical basis have led to a detailed translocation mechanism model.
Area of Science:
- Molecular Biology
- Cell Biology
- Biochemistry
Background:
- Most bacterial secretory proteins are translocated across the cytoplasmic membrane.
- Protein translocation is essential for bacterial viability and function.
- The SecYEG translocase and SecA motor protein are key components of this process.
Purpose of the Study:
- To elucidate the detailed mechanism of bacterial protein translocation.
- To integrate structural and biochemical data into a comprehensive model.
- To understand the role of ancillary factors like SecDF in translocation.
Main Methods:
- Structural biology techniques (e.g., cryo-EM, X-ray crystallography).
- Biochemical assays to study protein-protein interactions and motor activity.
- In vivo and in vitro translocation experiments.
Main Results:
- Detailed structural insights into the SecYEG channel and SecA motor.
- Biochemical characterization of the ATP-dependent motor activity of SecA.
- Elucidation of the function of the SecDF complex in facilitating translocation.
- Integration of data to propose a refined model of the translocation mechanism.
Conclusions:
- The SecYEG translocase and SecA motor work in concert to drive protein translocation.
- The SecDF complex plays a crucial role in the later stages of protein export.
- Recent advances have significantly improved our understanding of this fundamental cellular process.
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