An RNase III-processed sRNA coordinates sialic acid metabolism of Salmonella enterica during gut colonization

To study the biological function of the novel 3′ UTR-derived sRNA, ManS, originating from a S. enterica-specific genomic island, STM1127-STM1131, we conducted RNA-pulse expression combined with RNA sequencing to screen for mRNAs repressed by ManS. Additionally, we compared the transcriptomic changes between wild-type and ManS-deleted strains during N-acetylmannosamine (ManNAc) metabolism. RNA-pulse Expression Combined with RNA Sequencing:The 80-nt full-length ManS sequence was cloned downstream of the PBAD promoter in a plasmid, and its expression was induced with L-arabinose for 10 minutes in a Salmonella ManS-deleted strain grown in M9CA medium supplemented with 0.1% ManNAc at OD600 ~0.5. An empty pBAD plasmid served as a control under the same conditions. Total RNA was isolated and treated with DNase I, and non-stranded libraries were prepared for RNA sequencing.Comparing Transcriptomic Changes between Wild-Type and ManS-Deleted Strains during N-Acetylmannosamine Metabolism:Wild-type and ManS-deleted Salmonella strains were grown in M9CA medium supplemented with 0.1% ManNAc to an OD600 of ~0.5. Total RNA was isolated and treated with DNase I, and stranded libraries were prepared for RNA sequencing to compare the transcriptomic changes between the two strains.