Rhythmic transcription in cyanobacteria

地球上的生命依赖于太阳的光和热。蓝藻是地球上最大的生物群之一，它们利用太阳的能量来固定二氧化碳，并在光合作用中产生氧气。蓝藻已经进化出以24小时为周期调节其基因活动的能力。这些周期不仅基于实际的昼夜周期，而且还支持内部昼夜节律分子钟，使蓝藻能够预测白天和黑夜的开始。光依赖性和昼夜节律信息由RNA聚合酶（RNAP）整理并转化为基因表达的节律模式。这些信息是如何被RNAP破译的尚不清楚。我们的目标是通过生物信息学、生物化学、蛋白质组学和冷冻电镜技术来表征RNAP、转录因子和DNA调控元件参与基因的昼夜激活/抑制的结构域。在前期工作中，我们建立了易于操作的体外转录和昼夜调节实验系统，并获得了蓝藻RNAP复合物的前两个结构，并得到了生化和蛋白质组学数据的支持。该项目将产生蓝藻的基本知识，谁是全球碳循环的主要贡献者。蓝藻目前作为碳中性生产者越来越受欢迎。我们的研究将为工业菌株的遗传和代谢工程提供信息。在未来，蓝藻生物钟移植到工业微生物中可能作为一种有吸引力的机制来调度复杂的生物合成任务。

Life on Earth depends on light and warmth of the Sun. One of the largest group of organisms on Earth is cyanobacteria who use energy of sun to fix cardon dioxide and produce oxygen during photosynthesis. Cyanobacteria have evolved the ability to regulate activity of their genes in cycles of 24 hours. These cycles are based not only on actual day/night cycles, but also supported by internal circadian molecular clock that allows cyanobacteria to predict the onset of day and night.Light-dependent and circadian- information is collated by RNA polymerase (RNAP) and transformed into rhythmic pattern of gene expression. How this information is deciphered by RNAP is not known. We aim to characterise domains of RNAP, transcription factors and DNA regulatory elements involved in circadian activation/repression of genes by using bioinformatics, biochemistry, proteomics and Cryo-EM microscopy. In preliminary work we developed tractable in vitro experimental system of transcription and circadian regulation, and obtained first two structures of cyanobacterial RNAP complexes, supported by biochemical and proteomics data.This project will generate fundamental knowledge of cyanobacteria, who are the main contributors in global carbon cycle. Cyanobacteria currently gaining popularity as carbon neutral producers. Our research will inform genetic and metabolic engineering of industrial strains. In the future cyanobacterial circadian clock transplanted into industrial microorganisms may serve as attractive mechanism to schedule complex biosynthetic tasks.