Integrated analysis of cyanobacteriochromes in diversity and molecular regulation of cyanobacterial photoresponses

我们发现蓝细菌具有多样的光感受器，蓝细菌色素在感知大范围的光颜色方面是独特的。本文从蓝藻色素的生物化学、结构和生理学等方面对蓝藻色素进行了研究，以期在分子水平上整合光信号系统。我们确定了两个蓝藻色素的晶体结构，并揭示了颜色调谐和分子内信号的原子基础。我们确定的蓝藻色素的酶促调节产生或降解的第二信使分子，环二鸟苷酸，诱导纤维素生产和细胞聚集在嗜热蓝藻。我们还阐明了蓝藻色素的分子贡献的细胞聚集的组合诱变研究。因此，一组蓝藻色素通过直接调节环状二鸟苷酸将各种光信号整合到纤维素生产和细胞聚集中。

We found that cyanobacteria possess diverse photoreceptors and cyanobacteriochromes are unique in perception of wide range of light color. We focused on biochemical, structural and physiological aspects of cyanobacteriochromes in order to integrate the light signaling system at molecular level. We determined the crystal structures of two cyanobacteriochromes and revealed the atomic basis for the color tuning and intramolecular signaling. We determined enzymatic regulation of the cyanobacteriochromes to produce or degrade a second messenger molecule, cyclic diguanylic acid, which induces cellulose production and cellular aggregation in thermophilic cyanobacteria. We also elucidated the molecular contribution of the cyanobacteriochromes to the cellular aggregation by combinatorial mutagenesis studies. Thus, a set of cyanobacteriochromes integrates various light signals into the cellulose production and cellular aggregation by direct regulation of cyclic diguanylic acid.