AmtB-mediated NH3 transport in prokaryotes must be active and as a consequence regulation of transport by GlnK is mandatory to limit futile cycling of NH4(+)/NH3.
FEBS Lett
; 585(1): 23-8, 2011 Jan 03.
Article
em En
| MEDLINE
| ID: mdl-21134373
ABSTRACT
The nature of the ammonium import into prokaryotes has been controversial. A systems biological approach makes us hypothesize that AmtB-mediated import must be active for intracellular NH(4)(+) concentrations to sustain growth. Revisiting experimental evidence, we find the permeability assays reporting passive NH(3) import inconclusive. As an inevitable consequence of the proposed NH(4)(+) transport, outward permeation of NH(3) constitutes a futile cycle. We hypothesize that the regulatory protein GlnK is required to fine-tune the active transport of ammonium in order to limit futile cycling whilst enabling an intracellular ammonium level sufficient for the cell's nitrogen requirements.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Escherichia coli
/
Proteínas de Transporte de Cátions
/
Proteínas PII Reguladoras de Nitrogênio
/
Amônia
/
Compostos de Amônio Quaternário
/
Nucleotidiltransferases
Idioma:
En
Revista:
FEBS Lett
Ano de publicação:
2011
Tipo de documento:
Article
País de afiliação:
Holanda