Mayer, Maria ; Dynowski, Marek ; Ludewig, Uwe (2006)
Ammonium ion transport by the AMT/Rh homologue LeAMT1;1.
In: The Biochemical journal, 396 (3)
Artikel, Bibliographie
Kurzbeschreibung (Abstract)
AMT (ammonium transporter)/Rh (Rhesus) ammonium transporters/channels are identified in all domains of life and fulfil contrasting functions related either to ammonium acquisition or excretion. Based on functional and crystallographic high-resolution structural data, it was recently proposed that the bacterial AmtB (ammonium transporter B) is a gas channel for NH3 [Khademi, O'Connell, III, Remis, Robles-Colmenares, Miercke and Stroud (2004) Science 305, 1587-1594; Zheng, Kostrewa, Berneche, Winkler and Li (2004) Proc. Natl. Acad. Sci. U.S.A. 101, 17090-17095]. Key residues, proposed to be crucial for NH3 conduction, and the hydrophobic, but obstructed, pore were conserved in a homology model of LeAMT1;1 from tomato. Transport by LeAMT1;1 was affected by mutations of residues that were predicted to constitute the aromatic recruitment site for NH4+ at the external pore entrance. Despite the structural similarities, LeAMT1;1 was shown to transport only the ion; each transported 14C-methylammonium molecule carried a single positive elementary charge. Similarly, NH4+ (or H+/NH3) was transported, but NH3 conduction was excluded. It is concluded that related proteins and a similar molecular architecture can apparently support contrasting transport mechanisms.
Typ des Eintrags: | Artikel |
---|---|
Erschienen: | 2006 |
Autor(en): | Mayer, Maria ; Dynowski, Marek ; Ludewig, Uwe |
Art des Eintrags: | Bibliographie |
Titel: | Ammonium ion transport by the AMT/Rh homologue LeAMT1;1 |
Sprache: | Englisch |
Publikationsjahr: | 2006 |
Titel der Zeitschrift, Zeitung oder Schriftenreihe: | The Biochemical journal |
Jahrgang/Volume einer Zeitschrift: | 396 |
(Heft-)Nummer: | 3 |
Kurzbeschreibung (Abstract): | AMT (ammonium transporter)/Rh (Rhesus) ammonium transporters/channels are identified in all domains of life and fulfil contrasting functions related either to ammonium acquisition or excretion. Based on functional and crystallographic high-resolution structural data, it was recently proposed that the bacterial AmtB (ammonium transporter B) is a gas channel for NH3 [Khademi, O'Connell, III, Remis, Robles-Colmenares, Miercke and Stroud (2004) Science 305, 1587-1594; Zheng, Kostrewa, Berneche, Winkler and Li (2004) Proc. Natl. Acad. Sci. U.S.A. 101, 17090-17095]. Key residues, proposed to be crucial for NH3 conduction, and the hydrophobic, but obstructed, pore were conserved in a homology model of LeAMT1;1 from tomato. Transport by LeAMT1;1 was affected by mutations of residues that were predicted to constitute the aromatic recruitment site for NH4+ at the external pore entrance. Despite the structural similarities, LeAMT1;1 was shown to transport only the ion; each transported 14C-methylammonium molecule carried a single positive elementary charge. Similarly, NH4+ (or H+/NH3) was transported, but NH3 conduction was excluded. It is concluded that related proteins and a similar molecular architecture can apparently support contrasting transport mechanisms. |
Fachbereich(e)/-gebiet(e): | 10 Fachbereich Biologie > Pflanzenernährung und Biomasse ?? fb10_botanik ?? 10 Fachbereich Biologie |
Hinterlegungsdatum: | 16 Mär 2010 14:07 |
Letzte Änderung: | 05 Mär 2013 09:32 |
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