Heilmann Monika, Christie John M, Kennis John T M, Jenkins Gareth I, Mathes Tilo
Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, Bower Building, University of Glasgow, Glasgow G12 8QQ, UK.
Photochem Photobiol Sci. 2015 Feb;14(2):252-7. doi: 10.1039/c4pp00246f.
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%.
植物光感受器UVR8二聚体界面处的色氨酸残基通过一种迄今未知的机制，在吸收UV-B后促进单体化。利用傅里叶变换红外光谱，我们将UVR8光诱导的结构转变主要归因于氨基酸侧链，而生理相关的C端延伸的二级结构没有重大转变。此外，我们将UVR8色氨酸发射中与单体化相关的增加和红移分别归因于色氨酸侧链的光诱导重排和天冬氨酸残基D96和D107的重新定位。通过光照依赖发射光谱，我们还测定了光诱导单体化的量子产率为20±8%。
