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Examining the Conformational Dynamics of Membrane Proteins in situ with Site-directed Fluorescence Labeling
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Monitoring the binding and insertion of a single transmembrane protein by an insertase
Pawel R Laskowski1, Kristyna Pluhackova1, Maximilian Haase2
1Department of Biosystems Science and Engineering, ETH Zurich, 4058, Basel, Switzerland.
Nature Communications
|December 7, 2021
Summary
Researchers studied how the bacterial insertase YidC inserts membrane proteins. Using advanced techniques, they found YidC binds and transfers proteins to the membrane, aiding their proper folding and insertion.
Area of Science:
- Biochemistry
- Molecular Biology
- Cell Biology
Background:
- Cells use insertases and translocases for membrane protein insertion and folding.
- The precise mechanisms of insertase function remain incompletely understood.
Purpose of the Study:
- To elucidate the mechanism by which the bacterial insertase YidC facilitates membrane protein insertion and folding.
- To investigate the dynamic interactions between YidC and the membrane protein Pf3 during insertion.
Main Methods:
- Single-molecule force spectroscopy
- Fluorescence spectroscopy
- Molecular dynamics simulations
Main Results:
- YidC's cytoplasmic α-helical hairpin rapidly binds Pf3 with high conformational variability.
- YidC facilitates Pf3 transfer to a stable, membrane-inserted, folded state within milliseconds.
- The inserted Pf3 protein exhibits low conformational variability characteristic of transmembrane proteins.
Conclusions:
- YidC utilizes its hairpin and groove to mediate membrane protein binding and insertion.
- This mechanistic insight into YidC function is relevant for understanding membrane protein biogenesis across all domains of life.
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