RNA polymerase

Components of the RNA polymerase

Core subunits

• RpoA: alpha subunit
• RpoB: beta subunit
• RpoC: beta' subunit

• The stoichiometry of the enzyme is RpoA(2)-RpoB-RpoC

Sigma factors

• In addition to the housekeeping sigma factor, SigA, there are several other sigma factors with different promoter recognition specifiity that are active under specific conditions (such as stress or sporulation)

Small accessory subunits

• RpoE: delta subunit
• YloH: omega subunit

Other temporary components

• NusA: essential elongation factor