Biochemical and functional characterization of BLUF-type flavin-binding proteins of two species of cyanobacteria.
Biochemical and functional characterization of BLUF-type flavin-binding proteins of two species of cyanobacteria.
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DOI：
10.1093/jb/mvi089
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发表时间：
2005-06
影响因子：
2.7
通讯作者：
K. Okajima;Shizue Yoshihara;Y. Fukushima;Xiaoxing Geng;Mitsunori Katayama;S. Higashi;Masakatsu Watanabe-Masakatsu-Wat
中科院分区：
文献类型：
--
作者：
K. Okajima;Shizue Yoshihara;Y. Fukushima;Xiaoxing Geng;Mitsunori Katayama;S. Higashi;Masakatsu Watanabe-Masakatsu-Wat
BLUF（a sensor of Blue-Light Using FAD）是一种新型的光感受器结构域，广泛存在于细菌和一些真核藻类中。如在基因组分析中发现的，某些蓝细菌具有带有短C-末端延伸的BLUF蛋白。作为典型的例子，对来自嗜热细长聚球藻BP-1的Tll 0078和来自中温集胞藻PCC 6803的Slr 1694进行了比较研究。这两种蛋白质的FAD几乎没有减少外源性还原剂或介质，但甲基紫精，但表现出典型的光谱位移到一个较长的波长激发蓝光。特别是，新鲜制备的Tll 0078蛋白显示出缓慢但可逆的聚集，表明光诱导的蛋白质结构的构象变化。从黄素荧光判断，Tll 0078比Slr 1694热处理稳定得多。slr 1694-破坏物显示趋光运动远离光源（负趋光性），而野生型集胞藻显示正趋光性朝向源。用slr 1694筛选酵母双杂交显示了slr 1694（PixD）与自身的相互作用以及与新型PatA样反应调节剂Slr 1693（PixE）的相互作用。这些结果进行了讨论的关系的“短”BLUF蛋白在蓝藻趋光性的调节信号机制。
BLUF (a sensor of Blue-Light Using FAD) is a novel putative photoreceptor domain that is found in many bacteria and some eukaryotic algae. As found on genome analysis, certain cyanobacteria have BLUF proteins with a short C-terminal extension. As typical examples, Tll0078 from thermophilic Thermosynechococcus elongatus BP-1 and Slr1694 from mesophilic Synechocystis sp. PCC 6803 were comparatively studied. FAD of both proteins was hardly reduced by exogenous reductants or mediators except methylviologen but showed a typical spectral shift to a longer wavelength upon excitation with blue light. In particular, freshly prepared Tll0078 protein showed slow but reversible aggregation, indicative of light-induced conformational changes in the protein structure. Tll0078 is far more stable as to heat treatment than Slr1694, as judged from flavin fluorescence. The slr1694-disruptant showed phototactic motility away from the light source (negative phototaxis), while the wild type Synechocystis showed positive phototaxis toward the source. Yeast two-hybrid screening with slr1694 showed self-interaction of Slr1694 (PixD) with itself and interaction with a novel PatA-like response regulator, Slr1693 (PixE). These results were discussed in relation to the signaling mechanism of the "short" BLUF proteins in the regulation of cyanobacterial phototaxis.