EMD-35300

Single-particle
3.16 Å
EMD-35300 Deposition: 08/02/2023
Map released: 02/08/2023
Last modified: 30/10/2024
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links

EMD-35300

The Arabidopsis CLCa transporter bound with nitrate, ATP and PIP2

EMD-35300

Single-particle
3.16 Å
EMD-35300 Deposition: 08/02/2023
Map released: 02/08/2023
Last modified: 30/10/2024
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Sample Organism: Arabidopsis thaliana
Sample: The Arabidopsis CLCa transporter
Fitted models: 8iad (Avg. Q-score: 0.532)

Deposition Authors: Yang Z , Zhang X , Zhang P
Molecular mechanism underlying regulation of Arabidopsis CLCa transporter by nucleotides and phospholipids.
Yang Z , Zhang X , Ye S, Zheng J, Huang X , Yu F, Chen Z , Cai S , Zhang P
(2023) Nat Commun , 14 , 4879 - 4879
PUBMED: 37573431
DOI: doi:10.1038/s41467-023-40624-z
ISSN: 2041-1723
Abstract:
Chloride channels (CLCs) transport anion across membrane to regulate ion homeostasis and acidification of intracellular organelles, and are divided into anion channels and anion/proton antiporters. Arabidopsis thaliana CLCa (AtCLCa) transporter localizes to the tonoplast which imports NO3- and to a less extent Cl- from cytoplasm. The activity of AtCLCa and many other CLCs is regulated by nucleotides and phospholipids, however, the molecular mechanism remains unclear. Here we determine the cryo-EM structures of AtCLCa bound with NO3- and Cl-, respectively. Both structures are captured in ATP and PI(4,5)P2 bound conformation. Structural and electrophysiological analyses reveal a previously unidentified N-terminal β-hairpin that is stabilized by ATP binding to block the anion transport pathway, thereby inhibiting the AtCLCa activity. While AMP loses the inhibition capacity due to lack of the β/γ- phosphates required for β-hairpin stabilization. This well explains how AtCLCa senses the ATP/AMP status to regulate the physiological nitrogen-carbon balance. Our data further show that PI(4,5)P2 or PI(3,5)P2 binds to the AtCLCa dimer interface and occupies the proton-exit pathway, which may help to understand the inhibition of AtCLCa by phospholipids to facilitate guard cell vacuole acidification and stomatal closure. In a word, our work suggests the regulatory mechanism of AtCLCa by nucleotides and phospholipids under certain physiological scenarios and provides new insights for future study of CLCs.