How Do the Core Enzyme and the Holoenzyme of RNA

Question

How do the core enzyme and the holoenzyme of RNA polymerase differ in E. coli?
A) The holoenzyme includes the sigma (σ) subunit, the core enzyme does not.
B) The core enzyme includes the sigma (σ) subunit, the holoenzyme does not.
C) The holoenzyme transcribes from an RNA template, the core enzyme from a DNA template.
D) The core enzyme transcribes from an RNA template, the holoenzyme from a DNA template.

Accepted Answer

The holoenzyme of RNA polymerase in E. coli includes the sigma (σ) subunit, which is responsible for binding to specific promoter sequences on DNA and initiating transcription. The core enzyme lacks this subunit and is unable to recognize promoters on its own. Therefore, the holoenzyme is necessary for efficient transcription in E. coli.