Question

An in vitro transcription system that contains a bacterial gene initiates transcription but from random points on the DNA. Which of the following proteins MOST likely is missing from the reaction?

a) RNA polymerase
b) Sigma factor
c) Transcription factors
d) Promoter sequence

Answer 1

The missing protein is the Sigma factor, which helps the RNA polymerase recognize and bind to the promoter sequence of a gene for the correct initiation of transcription.

Step-by-step explanation:

The in vitro transcription system that initiates transcription from random points on the DNA is most likely missing the Sigma factor.

In bacteria, transcription is initiated by the association of a sigma factor with the RNA polymerase. The sigma factor helps the RNA polymerase recognize and bind to the promoter sequence of a gene, allowing for the start of transcription at the correct site. Without the sigma factor, the RNA polymerase binds randomly to the DNA and initiates transcription from random points.

Therefore, the missing protein in this reaction is the Sigma factor.