Figure 7.

Regulatory model of nitrogen assimilation proposed for A. ferrooxidans DSM 16786. Proteins (boxes) and their resulting functions (lines) are indicated in red for activation during low nitrogen conditions and in blue during high nitrogen condition. In green are identified the principal effectors and nitrogen source that trigger the activation/inactivation of the enzymes involved in the model: ammonia (NH3), molecular nitrogen (N2), glutamine and 2-oxoglutarate. In orange are represented the signal transducer proteins: GlnD (uridylyltransferase), NtrB (Nitrogen regulation protein ntrB) and GlnE (Glutamate-ammonia-ligase adenylyltransferase). It is important to mention that this model considers the role of NifA in activating target genes under low nitrogen conditions.