8HYA

Cryo-EM structure of Arabidopsis thaliana SOS1 in an occluded state, with expanded TMD

Summary for 8HYA

• Entry DOI: 10.2210/pdb8hya/pdb
• EMDB information: 35085
• Descriptor: Sodium/hydrogen exchanger 7, HEXADECANE (2 entities in total)
• Functional Keywords: sodium/proton antiporter, membrane protein
• Biological source: Arabidopsis thaliana (thale cress)
• Total number of polymer chains: 2
• Total formula weight: 256014.43

Authors

Wang, Y.,Zhao, Y.,Gao, Y. (deposition date: 2023-01-06, release date: 2023-08-09, Last modification date: 2025-06-18)

Primary citation

Wang, Y.,Pan, C.,Chen, Q.,Xie, Q.,Gao, Y.,He, L.,Li, Y.,Dong, Y.,Jiang, X.,Zhao, Y.
Architecture and autoinhibitory mechanism of the plasma membrane Na + /H + antiporter SOS1 in Arabidopsis.
Nat Commun, 14:4487-4487, 2023

PubMed Abstract: Salt-overly-sensitive 1 (SOS1) is a unique electroneutral Na/H antiporter at the plasma membrane of higher plants and plays a central role in resisting salt stress. SOS1 is kept in a resting state with basal activity and activated upon phosphorylation. Here, we report the structures of SOS1. SOS1 forms a homodimer, with each monomer composed of transmembrane and intracellular domains. We find that SOS1 is locked in an occluded state by shifting of the lateral-gate TM5b toward the dimerization domain, thus shielding the Na/H binding site. We speculate that the dimerization of the intracellular domain is crucial to stabilize the transporter in this specific conformation. Moreover, two discrete fragments and a residue W1013 are important to prevent the transition of SOS1 to an alternative conformational state, as validated by functional complementation assays. Our study enriches understanding of the alternate access model of eukaryotic Na/H exchangers.

PubMed: 37495621
DOI: 10.1038/s41467-023-40215-y

Experimental method

ELECTRON MICROSCOPY (3.4 Å)