The structure of Arabidopsis phytochrome A reveals topological and functional diversification among the plant photoreceptor isoforms.

ABSTRACT: Plants employ a divergent cohort of phytochrome (Phy) photoreceptors to govern many aspects of morphogenesis through reversible photointerconversion between inactive Pr and active Pfr conformers. The two most influential are PhyA whose retention of Pfr enables sensation of dim light, while the relative instability of Pfr for PhyB makes it better suited for detecting full sun and temperature. To better understand these contrasts, we solved, by cryo-electron microscopy, the three-dimensional structure of full-length PhyA as Pr. Like PhyB, PhyA dimerizes through head-to-head assembly of its C-terminal histidine kinase-related domains (HKRDs), while the remainder assembles as a head-to-tail light-responsive platform. Whereas the platform and HKRDs associate asymmetrically in PhyB dimers, these

SUBMITTER: Burgie ES 

PROVIDER: S-EPMC10546791 | biostudies-literature | 2023 Jul

REPOSITORIES: biostudies-literature