Choose the Description Below That Best Matches the Current Model

Question

Choose the description below that best matches the current model of RNA polymerase holoenzyme.
A)A core enzyme composed of five polypeptides bound by a transcription factor.
B)A core enzyme composed of five polypeptides bound by ribosomes.
C)A core enzyme composed of five sigma factors bound by a polypeptide chain.
D)An open complex or "bubble" formed by DNA,mRNA,and RNA polymerase.

Accepted Answer

The RNA polymerase holoenzyme in bacteria is composed of the core enzyme, which includes five polypeptides (two alpha subunits, one beta subunit, one beta' subunit, and one omega subunit), and a sigma factor. The sigma factor is a transcription factor that helps the core enzyme recognize the start sites of genes (promoters), enabling the initiation of transcription.