par Williamson, Gordon;Tamburrino, Giulia;Bizior, Adriana;Boeckstaens, Mélanie 
;Mirandela, Gaëtan Dias;Bage, Marcus;Pisliakov, Andrei;Ives, Callum C.M.;Terras, Eilidh;Hoskisson, Paul P.A.;Marini, Anna Maria ;Zachariae, Ulrich;Javelle, Arnaud
Référence eLife, 9, page (1-41), e57183
Publication Publié, 2020-07-01
;Mirandela, Gaëtan Dias;Bage, Marcus;Pisliakov, Andrei;Ives, Callum C.M.;Terras, Eilidh;Hoskisson, Paul P.A.;Marini, Anna Maria ;Zachariae, Ulrich;Javelle, ArnaudRéférence eLife, 9, page (1-41), e57183
Publication Publié, 2020-07-01
Article révisé par les pairs
| Résumé : | The transport of charged molecules across biological membranes faces the dual problem of accommodating charges in a highly hydrophobic environment while maintaining selective substrate translocation. This has been the subject of a particular controversy for the exchange of ammonium across cellular membranes, an essential process in all domains of life. Ammonium transport is mediated by the ubiquitous Amt/Mep/Rh transporters that includes the human Rhesus factors. Here, using a combination of electrophysiology, yeast functional complementation and extended molecular dynamics simulations, we reveal a unique two-lane pathway for electrogenic NH4+ transport in two archetypal members of the family, the transporters AmtB from Escherichia coli and Rh50 from Nitrosomonas europaea. The pathway underpins a mechanism by which charged H+ and neutral NH3 are carried separately across the membrane after NH4+ deprotonation. This mechanism defines a new principle of achieving transport selectivity against competing ions in a biological transport process. |
