The oligomeric structures of plant cryptochromes.
Shao, K., Zhang, X., Li, X., Hao, Y., Huang, X., Ma, M., Zhang, M., Yu, F., Liu, H., Zhang, P.(2020) Nat Struct Mol Biol 27: 480-488
- PubMed: 32398825 
- DOI: https://doi.org/10.1038/s41594-020-0420-x
- Primary Citation of Related Structures:  
6LZ3, 6LZ7 - PubMed Abstract: 
Cryptochromes (CRYs) are a group of evolutionarily conserved flavoproteins found in many organisms. In plants, the well-studied CRY photoreceptor, activated by blue light, plays essential roles in plant growth and development. However, the mechanism of activation remains largely unknown. Here, we determined the oligomeric structures of the blue-light-perceiving PHR domain of Zea mays CRY1 and an Arabidopsis CRY2 constitutively active mutant. The structures form dimers and tetramers whose functional importance is examined in vitro and in vivo with Arabidopsis CRY2. Structure-based analysis suggests that blue light may be perceived by CRY to cause conformational changes, whose precise nature remains to be determined, leading to oligomerization that is essential for downstream signaling. This photoactivation mechanism may be widely used by plant CRYs. Our study reveals a molecular mechanism of plant CRY activation and also paves the way for design of CRY as a more efficient optical switch.
Organizational Affiliation: 
National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.