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bioRxiv · 10.1101/2022.12.21.521437

Structural and functional properties of a plant NRAMP related aluminum transporter

Ramanadane, K.·Liziczai, M.·Markovic, D.·Straub, M. S.·Rosalen, G. T.·Udovcic, A.·Dutzler, R.·Manatschal, C.
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Abstract

The transport of transition metal ions by members of the SLC11/NRAMP family constitutes a ubiquitous mechanism for the uptake of Fe2+ and Mn2+ across all kingdoms of life. Despite the strong conservation of the family, two of its branches have evolved a distinct substrate preference with one mediating Mg2+ uptake in prokaryotes and another the transport of Al3+ into plant cells. Our previous work on the SLC11 transporter from Eggerthella lenta revealed the basis for its Mg2+ selectivity (Ramanadane et al., 2022). Here we have addressed the structural and functional properties of a putative Al3+ transporter from Setaria italica. We show that the protein transports diverse divalent metal ions and binds the trivalent ions Al3+ and Ga3+, which are both presumable substrates. Its cryo-EM structure displays an occluded conformation that is closer to an inward-than an outward-facing state with a binding site that is remodeled to accommodate the increased charge density of its transported substrate.

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Ramanadane, K., Liziczai, M., Markovic, D., Straub, M. S., Rosalen, G. T., Udovcic, A., Dutzler, R., Manatschal, C.. 2022-12-23. Structural and functional properties of a plant NRAMP related aluminum transporter. https://doi.org/10.1101/2022.12.21.521437

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