Abstract
AIM: This study aims to explore the role of propionylation at the K32 residue of the global regulator Fis in Salmonella enterica serovar Typhi (S. Typhi) and its influence on the pathogenicity of the bacteria. MATERIALS & METHODS: Bacterial strains were cultured in media with sodium propionate supplementation. The propionylation status of Fis was determined through Western blot and mass spectrometry analyses. The DNA-binding capability of Fis was assessed using EMSA. The invasion and survival capacities of S. Typhi were examined using T84 cells and THP-1 macrophages. RESULTS: Propionylation at the K32 site of Fis was found to down-regulate its DNA-binding ability, leading to a reduction in the invasion and survival of S. Typhi within host cells. The K32Q mutant exhibited significantly decreased invasion and survival capabilities compared to the wild-type and K32R mutant strains. CONCLUSION: Propionylation of Fis at the K32 residue impacts the pathogenicity of S. Typhi, shedding light on the role of post-translational modifications in bacterial infections.