Question

Regulatory proteins are the accessory proteins that interact with RNA polymerase and affect its role in transcription. Which of the following statements is correct about regulatory protein?

• A. They only increase expression.
• B. They only decrease expression.
• C. They interact with RNA polymerase but do not affect the expression.
• D. They can act both as activators and as repressors.

Answer 1

The correct option is D They can act both as activators and as repressors.

In a transcription unit, th.e activity of RNA polymerase at a given promoter is regulated by interaction with accessory proteins, which affect its ability to recognise start sites. These regulatory proteins can act both positively (activators) and negatively (repressors).