Presence of a second mechanism for the posttranslational regulation of nitrogenase activity in Azospirillum brasilense in response to ammonium.
J Bacteriol
; 178(10): 2948-53, 1996 May.
Article
em En
| MEDLINE
| ID: mdl-8631686
Although ADP-ribosylation of dinitrogenase reductase plays a significant role in the regulation of nitrogenase activity in Azospirillum brasilense, it is not the only mechanism of that regulation. The replacement of an arginine residue at position 101 in the dinitrogenase reductase eliminated this ADP-ribosylation and revealed another regulatory system. While the constructed mutants had a low nitrogenase activity, NH4+ still partially inhibited their nitrogenase activity, independent of the dinitrogenase reductase ADP-ribosyltransferase/dinitrogenase reductase activating glycohydrolase (DRAT/DRAG) system. These mutated dinitrogenase reductases also were expressed in a Rhodospirillum rubrum strain that lacked its endogenous dinitrogenase reductase, and they supported high nitrogenase activity. These strains neither lost nitrogenase activity nor modified dinitrogenase reductase in response to darkness and NH4+, suggesting that the ADP-ribosylation of dinitrogenase reductase is probably the only mechanism for posttranslational regulation of nitrogenase activity in R. rubrum under these conditions.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Azospirillum brasilense
/
Regulação Bacteriana da Expressão Gênica
/
Processamento de Proteína Pós-Traducional
/
Compostos de Amônio Quaternário
/
Nitrogenase
/
N-Glicosil Hidrolases
País/Região como assunto:
America do sul
/
Brasil
Idioma:
En
Revista:
J Bacteriol
Ano de publicação:
1996
Tipo de documento:
Article
País de afiliação:
Estados Unidos
País de publicação:
Estados Unidos