Begin is the common term: to begin knitting a sweater. Commence is a more formal word, often suggesting a more prolonged or elaborate beginning: to commence proceedings in court. Initiate implies an active and often ingenious first act in a new field: to initiate a new procedure.
Structure of the trp operon. The trp operon is an operon â a group of genes that are used, or transcribed, together â that codes for the components for production of tryptophan. The trp operon is present in many bacteria, but was first characterized in Escherichia coli.The operon is regulated so that when tryptophan is present in the environment, the genes for tryptophan synthesis are not expressed.It was an important experimental system for learning about gene regulation, and is commonly used to teach gene regulation.he trp operon is present in many bacteria, but was first characterized in Escherichia coli. The operon is regulated so that when tryptophan is present in the environment, the genes for tryptophan synthesis are not expressed.
This single step is catalyzed by tryptophan synthetase, an enzyme that is a multimer of two proteins that are the product of the B and A genes. As with all operons, the trp operon consists of the repressor, promoter, operator and the structural genes. In this system, though, unlike the lac operon, the gene for the repressor is not adjacent to the promoter, but rather is located in another part of the E. coli genome.