Structure and function of an Arabidopsis thaliana sulfate transporter.Wang, L., Chen, K., Zhou, M.
(2021) Nat Commun 12: 4455-4455
- PubMed: 34294705
- DOI: https://doi.org/10.1038/s41467-021-24778-2
- Primary Citation of Related Structures:
- PubMed Abstract:
Plant sulfate transporters (SULTR) mediate absorption and distribution of sulfate (SO 4 2- ) and are essential for plant growth; however, our understanding of their structures and functions remains inadequate. Here we present the structure of a SULTR from Arabidopsis thaliana, AtSULTR4;1, in complex with SO 4 2- at an overall resolution of 2.8 Å. AtSULTR4;1 forms a homodimer and has a structural fold typical of the SLC26 family of anion transporters. The bound SO 4 2- is coordinated by side-chain hydroxyls and backbone amides, and further stabilized electrostatically by the conserved Arg393 and two helix dipoles. Proton and SO 4 2- are co-transported by AtSULTR4;1 and a proton gradient significantly enhances SO 4 2- transport. Glu347, which is ~7 Å from the bound SO 4 2- , is required for H + -driven transport. The cytosolic STAS domain interacts with transmembrane domains, and deletion of the STAS domain or mutations to the interface compromises dimer formation and reduces SO 4 2- transport, suggesting a regulatory function of the STAS domain.
Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA.