Val43 residue of NsrR is crucial for the nitric oxide response of Salmonella Typhimurium.

NsrR offers valuable insights into the Hmp modulation under NO stress. Furthermore, the observed amino acid polymorphisms in the α3 helices of NsrR proteins across different bacterial species suggest the diverse evolution of NsrR structure and gene regulation in response to varying levels of NO pressure within their ecological niches.