Examples of operon regulation: trp operon mechanism
Tryptophan can bind to the regulator protein, activating it and causing it to bind to the operator sequence. This inhibits trp operon expression.
- When tryptophan is absent, no regulator is bound to the operator and the genes are expressed.
- When tryptophan is present, the regulator binds to the operator and the genes are not expressed.
The trp operon is a negative repressible system.
Tryptophan is a small amino acid. When tryptophan is present, the trp operator is switched off and stops the synthesis of the amino acid.