The tryptophan (trp) operon

Transcription is initiated from the promoter trpP and progresses through the tryptophan leader (trpL) region to transcribe the five operon genes (trpE to trpA) into a polycistronic mRNA. The protein products of the operon genes catalyze successive steps of tryptophan synthesisTranscription is initiated from the promoter trpP and progresses through the tryptophan leader (trpL) region to transcribe the five operon genes (trpE to trpA) into a polycistronic mRNA. The protein products of the operon genes catalyze successive steps of tryptophan synthesis

Transcription- termination site 150bp162bp 6800 bp—vl P t l i \i\ romo er I | . Attenuator . . Operator I region Transcription Leader region Polycistronic mRNA Leader Translation 1 l l l 1 Polypeptides Anthranilate Anthraniiate PRA isomerase— Tryptophan Tryptophan synthetase synthetase InGP synthetase synthetase B synthetase a component I component ll L—T—l (PRA synthetase) | i Enzyme complexes IZII2 “232 Reactions Chorismate rim PRA—> CdRP —>lnGP 7L Tryptophan catalyzed . r . + glutamlne + PRPP + serlne PRPP: Phosphoribosyl pyrophosphate PRA = Phosphoribosyl anthranilate Cd RP: 1—(o-carboxyphenylamino)—1-deoxyribulose S—phosphate InGP = Indole-3-qlvcerol phosphate