Azorhizobium caulinodans P II and GlnK Proteins Control Nitrogen Fixation and Ammonia Assimilation

Nathalie Michel-Reydellet (1) , Pierre-Alexandre Kaminski (1)

1 Physiologie Cellulaire

We herein report that Azorhizobium caulinodans P II and GlnK are not necessary for glutamine synthetase (GS) adenylylation whereas both proteins are required for complete GS deadenylylation. The disruption of both glnB and glnK resulted in a high level of GS adenylylation under the condition of nitrogen fixation, leading to ammonium excretion in the free-living state. P II and GlnK also controlled nif gene expression because NifA activated nifH transcription and nitrogenase activity was derepressed in glnB glnK double mutants, but not in wild-type bacteria, grown in the presence of ammonia.

Domaines: Microbiologie et Parasitologie

Nathalie Michel-Reydellet, Pierre-Alexandre Kaminski. Azorhizobium caulinodans P II and GlnK Proteins Control Nitrogen Fixation and Ammonia Assimilation. Journal of Bacteriology, 1999, 181 (8), pp.2655-2658. ⟨10.1128/JB.181.8.2655-2658.1999⟩. ⟨pasteur-03659858⟩