Uptake mechanism of iron-phytosiderophore from the soil based on the structure of yellow stripe transporter.
Yamagata, A., Murata, Y., Namba, K., Terada, T., Fukai, S., Shirouzu, M.(2022) Nat Commun 13: 7180-7180
- PubMed: 36424382 
- DOI: https://doi.org/10.1038/s41467-022-34930-1
- Primary Citation of Related Structures:  
7WSR, 7WST, 7WSU - PubMed Abstract: 
Calcareous soils cover one-third of all land and cause severe growth defects in plants due to the poor water solubility of iron at high pH. Poaceae species use a unique chelation strategy, whereby plants secrete a high-affinity metal chelator, known as phytosiderophores (mugineic acids), and reabsorb the iron-phytosiderophore complex by the yellow stripe 1/yellow stripe 1-like (YS1/YSL) transporter for efficient uptake of iron from the soil. Here, we present three cryo-electron microscopy structures of barley YS1 (HvYS1) in the apo state, in complex with an iron-phytosiderophore complex, Fe(III)-deoxymugineic acid (Fe(III)-DMA), and in complex with the iron-bound synthetic DMA analog (Fe(III)-PDMA). The structures reveal a homodimeric assembly mediated through an anti-parallel β-sheet interaction with cholesterol hemisuccinate. Each protomer adopts an outward open conformation, and Fe(III)-DMA is bound near the extracellular space in the central cavity. Fe(III)-PDMA occupies the same binding site as Fe(III)-DMA, demonstrating that PDMA can function as a potent fertilizer in an essentially identical manner to DMA. Our results provide a structural framework for iron-phytosiderophore recognition and transport by YS1/YSL transporters, which will enable the rational design of new, high-potency fertilizers.
Organizational Affiliation: 
Laboratory for Protein Functional and Structural Biology, RIKEN Center for Biosystems Dynamics Research, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, Japan. atsushi.yamagata@riken.jp.