Hendrischk Anne-Kathrin, Moldt Julia, Frühwirth Sebastian Walter, Klug Gabriele
Institut für Mikro- und Molekularbiologie, Justus-Liebig-Universität Giessen, Heinrich-Buff-Ring, Giessen, Germany.
Photochem Photobiol. 2009 Sep-Oct;85(5):1254-9. doi: 10.1111/j.1751-1097.2009.00554.x. Epub 2009 Apr 6.
The facultatively phototrophic purple bacterium Rhodobacter sphaeroides 2.4.1 harbors a LOV (light, oxygen and voltage) domain protein, which shows a particular structure. LOV domains perceive blue light by a noncovalently bound flavin and transmit the signal to various coupled output domains. Proteins, that harbor a LOV core, function e.g. as phototropins or circadian clock regulators. Jalpha helices, which act as linker between the LOV core and the output domain, were shown to be involved in the light-dependent activation of the output domain. Like PpSB2 from Pseudomonas putida, the LOV domain protein of R. sphaeroides is not coupled to an effector domain and harbors an extended C-terminal alpha helix. We expressed the R. sphaeroides LOV domain recombinantly in Escherichia coli. The protein binds an FMN as a cofactor and shows a photocycle typical for LOV domain containing proteins. In R. sphaeroides, we detected the protein as well in the cytoplasm as in the membrane fraction, which was not reported for other bacterial LOV domain proteins.
兼性光合紫色细菌球形红杆菌2.4.1含有一种具有特殊结构的LOV（光、氧和电压）结构域蛋白。LOV结构域通过非共价结合的黄素感知蓝光，并将信号传递给各种偶联的输出结构域。含有LOV核心的蛋白质，例如作为向光素或生物钟调节器发挥作用。作为LOV核心与输出结构域之间连接物的Jα螺旋被证明参与输出结构域的光依赖性激活。与恶臭假单胞菌的PpSB2一样，球形红杆菌的LOV结构域蛋白不与效应结构域偶联，并含有一个延长的C末端α螺旋。我们在大肠杆菌中重组表达了球形红杆菌的LOV结构域。该蛋白结合FMN作为辅因子，并显示出含有LOV结构域蛋白典型的光循环。在球形红杆菌中，我们在细胞质和膜组分中均检测到了该蛋白，这在其他细菌LOV结构域蛋白中未见报道。
