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bioRxiv · 10.1101/2021.10.17.464711

Structural and functional properties of a magnesium transporter of the SLC11/NRAMP family

Ramanadane, K.·Straub, M. S.·Dutzler, R.·Manatschal, C.
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Abstract

Members of the ubiquitous SLC11/NRAMP family catalyze the uptake of divalent transition metal ions into cells. They have evolved to efficiently select these trace elements from a large pool of Ca2+ and Mg2+, which are both orders of magnitude more abundant, and to concentrate them in the cytoplasm aided by the cotransport of H+ serving as energy source. In the present study, we have characterized a member of a distant clade of the family found in prokaryotes, termed NRMTs, that were proposed to function as transporters of Mg2+. The protein transports Mg2+ and Mn2+ but not Ca2+ by a mechanism that is not coupled to H+. Structures determined by cryo-EM and X-ray crystallography revealed a generally similar protein architecture compared to classical NRAMPs, with a restructured ion binding site whose increased volume provides suitable interactions with ions that likely have retained much of their hydration shell.

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Ramanadane, K., Straub, M. S., Dutzler, R., Manatschal, C.. 2021-10-19. Structural and functional properties of a magnesium transporter of the SLC11/NRAMP family. https://doi.org/10.1101/2021.10.17.464711

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