Fig. 9: Model of MicN-mediated regulatory mechanism in Salmonella.

During macrophage infection, Salmonella produces the small protein MicN, which interacts with the target protein RpoS and modulates its binding to RNAP. This interaction leads to the transcriptional reprogramming of Salmonella and allows Salmonella to adopt a low-energy metabolic strategy, thereby improving its adaptability within intracellular environments.