A pore-occluding phenylalanine gate prevents ion slippage through plant ammonium transporters.

ABSTRACT: Throughout all kingdoms of life, highly conserved transport proteins mediate the passage of ammonium across membranes. These transporters share a high homology and a common pore structure. Whether NH₃, NH₄⁺ or NH₃ + H⁺ is the molecularly transported substrate, still remains unclear for distinct proteins. High-resolution protein structures of several ammonium transporters suggested two conserved pore domains, an external NH₄⁺ recruitment site and a pore-occluding twin phenylalanine gate, to take over a crucial role in substrate determination and selectivity. Here, we show that while the external recruitment site seems essential for AtAMT1;2 function, single mutants of the double phenylalanine gate were not reduced

SUBMITTER: Ganz P 

PROVIDER: S-EPMC6856177 | biostudies-literature | 2019 Nov

REPOSITORIES: biostudies-literature