title: Photoinduced transformation of UVR8 monitored by vibrational and fluorescence spectroscopy.
abstract: Tryptophan residues at the dimer interface of the plant photoreceptor UVR8 promote monomerisation after UV-B absorption via a so far unknown mechanism. Using FTIR spectroscopy we assign light-induced structural transitions of UVR8 mainly to amino acid side chains without major transformations of the secondary structure of the physiologically relevant C-terminal extension. Additionally, we assign the monomerisation associated increase and red shift of the UVR8 tryptophan emission to a photoinduced rearrangement of tryptophan side chains and a relocation of the aspartic acid residues D96 and D107, respectively. By illumination dependent emission spectroscopy we furthermore determined the quantum yield of photoinduced monomerisation to 20 ± 8%.
authors.affiliation: Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, Bower Building, University of Glasgow, Glasgow G12 8QQ, UK.
authors.forename: Monika
authors.initials: M
authors.lastname: Heilmann
authors.forename: John M
authors.initials: JM
authors.lastname: Christie
authors.forename: John T M
authors.initials: JT
authors.lastname: Kennis
authors.forename: Gareth I
authors.initials: GI
authors.lastname: Jenkins
authors.forename: Tilo
authors.initials: T
authors.lastname: Mathes
mesh_terms: D029681:Arabidopsis Proteins / Q000737:chemistry* / Q000235:genetics; D002868:Chromosomal Proteins, Non-Histone / Q000737:chemistry* / Q000235:genetics; D008027:Light; D009154:Mutation; D055668:Photochemical Processes; D011487:Protein Conformation / Q000528:radiation effects; D013050:Spectrometry, Fluorescence; D017550:Spectroscopy, Fourier Transform Infrared; D014364:Tryptophan / Q000737:chemistry / Q000235:genetics; D014732:Vibration
chemical_list: D029681:Arabidopsis Proteins; D002868:Chromosomal Proteins, Non-Histone; C525052:Uvr8 protein, Arabidopsis; D014364:Tryptophan