Unlike other proteins that transport water or potassium, ammonium transporters (Amts) are special because they can tell ammonium apart from potassium and water. This special ability helped them evolve to become ammonium sensors. Exploring ammonium sensing in biological systems provides insights into essential processes, such as the regulation of nutrient uptake or cellular signaling.
Now a team of scientists from the University of Freiburg has characterised a new membrane protein, called Sd-Amt1, that allows microorganisms to repurpose ammonium transporters (Amts) as receptors.
The researchers looked at the structure of this receptor both with and without ammonium attached, at very high detail (down to 1.7 and 1.9 Ångstroms). This helped them understand how the receptor switches between “ON” (with ammonium) and “OFF” (without ammonium) states. The newly discovered protein uses ammonium cations as extracellular signals to increase the cytoplasmic level of the secondary messenger cyclic-di-GMP. It consists of a membrane-integral ammonium receptor domain linked to a cytoplasmic diguanylate cyclase transducer module.
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Unlike other proteins that transport water or potassium, ammonium transporters (Amts) are special because they can tell ammonium apart from potassium and water. This special ability helped them evolve to become ammonium sensors. Exploring ammonium sensing in biological systems provides insights into essential processes, such as the regulation of nutrient uptake or cellular signaling. Now […]
