UVR8 is a recently discovered UV-B photoreceptor with a homodimer as the active state. UV-B perception of an interfacial tryptophan (W285) causes dissociation of the dimer into two functional monomers. Here, we investigate the molecular mechanism behind UV perception by W285 in UVR8. We observed a significant quenching dynamics in about 150 ps within the interfacial four-tryptophan cluster and an unusual resonance energy transfer from the other ten tryptophans to the tryptophan cluster in 1-2 nanoseconds to enhance functional efficiency. With mutation of W285 to F, the quenching dynamics is highly suppressed in this intact mutant dimer and the overall fluorescence intensity dramatically increases by a factor of 6, indicating W285 as a dominant quencher. These results reveal a unique energy transfer mechanism for efficient UV perception and the critical functional role of W285 for primary quenching dynamics for initiating dimer dissociation to trigger the function.
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http://dx.doi.org/10.1021/jz402396k | DOI Listing |
Light Sci Appl
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Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, China.
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Department of Physics, Khalifa University of Science and Technology, Abu Dhabi, 127788, United Arab Emirates.
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Key Laboratory of Combinatorial Biosynthesis and Drug Discovery (Wuhan University), Ministry of Education, and Wuhan University School of Pharmaceutical Sciences, Wuhan 430071, China; Department of Pharmacy, Zhongnan Hospital of Wuhan University, School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071, China. Electronic address:
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Key Laboratory of Interfacial Reaction & Sensing Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China. Electronic address:
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Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran; Department of Medicinal Chemistry, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran. Electronic address:
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