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Updated: Jun 6, 2026
12:11
A Rhodopsin Transport Assay by High-Content Imaging Analysis
Published on: January 16, 2019
Anabaena sensory rhodopsin is a light-driven unidirectional rotor
Angela Strambi1, Bo Durbeej, Nicolas Ferré
1Dipartimento di Chimica, Università di Siena, Siena I-53100, Italy.
Summary
Anabaena sensory rhodopsin acts as a molecular rotor. Its retinal chromophore undergoes a 360° unidirectional rotation during its photochromic cycle, driven by light.
Area of Science:
- Biophysics
- Computational Chemistry
- Molecular Biology
Background:
- Sensory rhodopsins are light-activated proteins crucial for cellular responses.
- Understanding the molecular mechanisms of their photochromic cycles is key to their function.
Purpose of the Study:
- To develop a realistic computational model of Anabaena sensory rhodopsin.
- To investigate the light-driven isomerization of the retinal chromophore within the protein.
Main Methods:
- Quantum-mechanics/molecular-mechanics (QM/MM) protocol.
- Multiconfigurational quantum chemistry methods.
- Analysis of absorption spectra and photochromic intermediates (K and L).
Main Results:
- A validated computational model accurately reproduced experimental spectra.
- Photoisomerization involves a 180° counterclockwise rotation of the =C14-C15= moiety.
- A full 360° unidirectional rotation of the moiety occurs during the cycle.
Conclusions:
- Anabaena sensory rhodopsin functions as a biological molecular rotor.
- The =C14-C15= moiety's rotation drives the protein's photochromic cycle.
- This study provides atomic-level insight into a light-driven biological machine.
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