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14:13
Atomic Force Microscopy of Red-Light Photoreceptors Using PeakForce Quantitative Nanomechanical Property Mapping
Published on: October 24, 2014
A photochromic photoreceptor from a eubacterium.
Daisuke Suzuki1, Tomomi Kitajima-Ihara, Yuji Furutani
1Division of Biological Science; Graduate School of Science.
Communicative & Integrative Biology
|August 26, 2009
Summary
Sensory rhodopsin I (SRI), a light-sensing protein, was discovered in a eubacterium, Salinibacter ruber (SrSRI). This novel SrSRI exhibits similar photochemical properties and stability to archaeal SRI, opening new research avenues.
Area of Science:
- Microbiology
- Biochemistry
- Photobiology
Background:
- Sensory rhodopsin I (SRI) functions as a photo-sensory receptor, mediating opposing signals based on light color.
- SRI was previously believed to exist exclusively in archaea.
Purpose of the Study:
- To report the discovery and characterization of a novel functional SRI from the eubacterium Salinibacter ruber (SrSRI).
- To investigate the potential of SrSRI in understanding SRI structure-function relationships and cellular manipulation.
Main Methods:
- Amino acid sequence analysis comparing SrSRI to known archaeal SRI (HsSRI).
- Photochemical property assessment of SrSRI.
- Evaluation of SrSRI stability under varying salt conditions.
Main Results:
- A functional SRI (SrSRI) was identified in the eubacterium Salinibacter ruber.
- SrSRI shares 43% amino acid identity with HsSRI and retains key functional residues.
- SrSRI exhibits photochemical properties similar to HsSRI and demonstrates high stability, even in dilute salt solutions.
Conclusions:
- SrSRI represents the first identified eubacterial SRI, expanding the known phylogenetic distribution of this protein family.
- SrSRI's stability and functional similarity to HsSRI make it a valuable model for studying SRI-HtrI interactions and structural dynamics.
- The discovery of SrSRI offers new possibilities for exploring rhodopsin-based manipulation of cellular signaling pathways, particularly kinase activity.
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