What is the complete RNA polymerase called when all five subunits are present?
Core enzyme
α-holoenzyme
β-holoenzyme
Holoenzyme
When all five subunits, α, α, β, β', and σ, are present, the RNA polymerase is referred to as the holoenzyme. The holoenzyme performs transcription initiation and synthesis of mRNA with transcriptional specificity conferred by the σ subunit.
Option 4 is the correct answer.