FAQ: What are the other sigma factors in E.coli?

Besides the “housekeeping” sigma factor 70, other sigma factors in E.coli include:
  • σ19 (FecI) - the ferric citrate sigma factor, regulates the fec gene for iron transport. 
  • σ24 (RpoE) - the extracytoplasmic/extreme heat stress sigma factor.
  • σ28 (RpoF) - the flagellar sigma factor.
  • σ32 (RpoH) - the heat shock sigma factor, it is turned on when exposed to heat.
  • σ38 (RpoS) - the starvation/stationary phase sigma factor.
  • σ54 (RpoN) - the nitrogen-limitation sigma factor.