Biology 1002B Lecture Notes - Fall 2018 Lecture 15 - Trp operon, Repressor, Tryptophan
Document Summary
Operons bring several genes under the control of one promoter region instead of each gene having its own. This means that the message codes for multiple genes, not just one. There are start and stop codons throughout. Because the stop/start codons are so close, the ribosomes don"t get away, and there is only one sd box needed to dock ribosomes. Operator is a protein binding domain which is understood as double stranded dna. In the trp operon, it is making the biosynthetic things needed to manufacture tryptophan. If we can get tryptophan from the environment, we do not need to express these genes, and a repressor is able to bing onto the trpr. Promoter is regulated by the binding of a repressor onto the operator. This system can sense the presence of tryptophan and dramatically reduce transcription. Trp repressors work as a dimer when they bind to trp and can bind to the trp repress-operator complex.
