How does tryptophan act as a corepressor in this system?
- Acheck_circle
Tryptophan binds the inactive repressor and converts it to an active form that binds the operator.
- B
Tryptophan inactivates the operator by methylation.
- C
Tryptophan binds the operator directly.
- D
Tryptophan increases RNA polymerase processivity.
Explanation
The trp operon is repressible: tryptophan acts as a corepressor by binding the otherwise inactive repressor, enabling it to bind the operator and shut off trp biosynthesis when amino acid levels are high.