1. Small-angle X-ray scattering study of the kinetics of light-dark transition in a LOV protein.
- Author
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Röllen K, Granzin J, Batra-Safferling R, and Stadler AM
- Subjects
- Bacterial Proteins metabolism, Crystallography, X-Ray, Flavin Mononucleotide chemistry, Kinetics, Protein Domains, Protein Structure, Secondary, Spectrophotometry, Ultraviolet, X-Ray Diffraction, Flavoproteins metabolism, Oxygen metabolism, Photoreceptors, Microbial metabolism, Pseudomonas putida metabolism, Scattering, Small Angle
- Abstract
Light, oxygen, voltage (LOV) photoreceptors consist of conserved photo-responsive domains in bacteria, archaea, plants and fungi, and detect blue-light via a flavin cofactor. We investigated the blue-light induced conformational transition of the dimeric photoreceptor PpSB1-LOV-R66I from Pseudomonas putida in solution by using small-angle X-ray scattering (SAXS). SAXS experiments of the fully populated light- and dark-states under steady-state conditions revealed significant structural differences between the two states that are in agreement with the known structures determined by crystallography. We followed the transition from the light- to the dark-state by using SAXS measurements in real-time. A two-state model based on the light- and dark-state conformations could describe the measured time-course SAXS data with a relaxation time τREC of ~ 34 to 35 min being larger than the recovery time found with UV/vis spectroscopy. Unlike the flavin chromophore-based UV/vis method that is sensitive to the local chromophore environment in flavoproteins, SAXS-based assay depends on protein conformational changes and provides with an alternative to measure the recovery kinetics., Competing Interests: The authors have declared that no competing interests exist. Authors affiliation to Forschungszentrum Jülich GmbH does not alter our adherence to PLOS ONE policies on sharing data and materials.
- Published
- 2018
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