This gene has been named nur, ka tF, appR, csi-2, abrD , and rpoS . The techniques of molecular biology finally confirmed that these are all the same gene, now commonly called rpoS . Studies on rpoS identified a 1086 bp ORF that encoded a 41.5 kDa protein. The DNA sequence of rpoS indicated that it was closely related to the sigma 70 family of sigma factors. Cell morphology changes.
Cells become compact and sperical.
Induction of Salmonella typhimurium plasmid virulence genes. Trehalose synthesis increases. This leads to increased tolerance to osmotic and temperature stress, etc. Thus, the regulation of rpoS is complicated. RpoS availability is also regulated post-transcriptionally.