Structural insights into plant phytochrome A as a highly sensitized photoreceptor
Yuxuan Zhang, Xiaoli Lin, Chengying Ma, Jun Zhao, Xiaojin Shang, Zhengdong Wang, Bin Xu, Ning Gao, Xing Wang Deng, Jizong Wang
Abstract
Phytochromes (phys), first discovered in plants, are red and far-red photoreceptors that are also widely found in bacteria and fungi later. 1 , 2 Plant phys utilize the linear tetrapyrrole chromophore called photochromobilin (PΦB). Phys reversibly toggle between the red light-absorbing Pr and the far-red light-absorbing Pfr conformers by photoconversion, with absorption peaks at ~667 nm and ~730 nm, respectively. The Pfr conformer can be converted to Pr in darkness, a process called dark reversion or thermoreversion. 2 , 3 In plants, Pr conformers reside in the cytoplasm; and upon photoconversion, Pfr conformers are translocated into the nucleus, resulting in a plethora of physiological and developmental changes throughout the plant life cycle.