A conserved isoleucine in the LOV1 domain of a novel phototropin from the marine alga Ostreococcus tauri modulates the dark state recovery of the domain.
A conserved isoleucine in the LOV1 domain of a novel phototropin from the marine alga Ostreococcus tauri modulates the dark state recovery of the domain.
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来自海藻金牛骨球菌的新型趋光素的 LOV1 结构域中的保守异亮氨酸可调节该结构域的暗态恢复。
DOI：
10.1016/j.bbagen.2011.04.008
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
S. Kateriya
中科院分区：
文献类型：
--
作者：
S. K. Veetil;Chitvan Mittal;Peeyush Ranjan;S. Kateriya
背景趋光蛋白（Phototropins）是一类存在于光合自养生物中的UV-A/蓝光受体蛋白，其N端具有两个光-氧-电压（Light-Oxygen-Voltage，LOV）感受器结构域，C端具有一个激酶结构域。这是首次从海洋藻类Ostreococcusii中获得一种典型的光促素。tauri中，该结构域异源表达，纯化，并通过紫外-可见，荧光光谱和突变研究评估其光谱特性和暗恢复动力学。四级结构特征进行了研究，通过SEC和戊二醛crosslinking. ResultsOtLOV 1的吸收光谱缺乏的特征361 nm峰所示的其他LOV 1域。它经历了一个光循环，暗态恢复时间约为30 min（τ = 300.35 s）。天然OtLOV 1在水溶液中保持为二聚体，并且二聚体的形成与光和浓度无关。将43位异亮氨酸突变为缬氨酸使暗恢复时间加快10倍以上。将其突变为丝氨酸降低了对蓝光的敏感性，但黑暗恢复时间保持不变。结论新鉴定的OtPhot的OtLOV 1结构域具有功能性，其43位的异亮氨酸是决定FMN结合的关键残基。这是第一个表征的典型海洋光致伸缩蛋白的LOV 1结构域，其光谱性质与LOV 1结构域的光谱性质相似高等植物。
BackgroundPhototropins are UV-A/blue light receptor proteins with two LOV (Light-Oxygen-Voltage) sensor domains at their N terminus and a kinase domain at the C-terminus in photoautotrophic organisms. This is the first research report of a canonical phototropin from marine algae Ostreococcustauri.MethodsWe synthesized core LOV1 (OtLOV1) domain-encoding portion of the phototropin gene ofO. tauri, the domain was heterologously expressed, purified and assessed for its spectral properties and dark recovery kinetics by UV–Visible, fluorescence spectroscopy and mutational studies. Quaternary structure characteristics were studied by SEC and glutaraldehyde crosslinking.ResultsThe absorption spectrum of OtLOV1 lacks the characteristic 361 nm peak shown by other LOV1 domains. It undergoes a photocycle with a dark state recovery time of approximately 30 min (τ = 300.35 s). Native OtLOV1 stayed as dimer in aqueous solution and the dimer formation was light and concentration independent. Mutating isoleucine at 43rd position to valine accelerated the dark recovery time by more than 10-fold. Mutating it to serine reduced sensitivity to blue light, but the dark recovery time remained unaltered. I43S mutation also destabilized the FMN binding to a great extent.ConclusionThe OtLOV1 domain of the newly identified OtPhot is functional and the isoleucine at position 43 of OtLOV1 is the key residue responsible for fine-tuning the domain properties.General significanceThis is the first characterized LOV1 domain of a canonical phototropin from a marine alga and spectral properties of the domain are similar to that of the LOV1 domain of higher plants.
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影响因子：
2.9
作者：
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通讯作者：
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作者：
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DOI：
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发表时间：
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影响因子：
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作者：
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通讯作者：
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