Structural insight into PIF6-mediated red light signal transduction of plant phytochrome B.

ABSTRACT: The red/far-red light receptor phytochrome B (phyB) plays essential roles in regulating various plant development processes. PhyB exists in two distinct photoreversible forms: the inactive Pr form and the active Pfr form. phyB-Pfr binds phytochrome-interacting factors (PIFs) to transduce red light signals. Here, we determined the cryo-electron microscopy (cryo-EM) structures of the photoactivated phyB-Pfr‒PIF6 complex, the constitutively active mutant phyB^Y276H‒PIF6 complex, and the truncated phyBN^Y276H‒PIF6 complex. In these structures, two parallel phyB-Pfr molecules interact with one PIF6 molecule. Red light-triggered rotation of the PΦB D-ring leads to the conversion of hairpin loops into α helices and the "head-to-head" reassembly of phyB-Pfr N-terminal photosens

SUBMITTER: Jia H 

PROVIDER: S-EPMC12098889 | biostudies-literature | 2025 May

REPOSITORIES: biostudies-literature