Abstract
Abstract Tryptophanyl-tRNA synthetase, functioning in tandem with the repressor-operator system, mediates homeostatic regulation of tryptophan biosynthetic operon expression. Whereas the repressor, activated directly by tryptophan, binds to the operator and blocks the initiation of transcription at the trp promoter, tryptophanyl-tRNA synthetase apparently regulates the termination of transcription at the attenuator site between the operator and the structural genes of the operon. There is an inverse correlation between aminocylation of tRNA Trp and expression of the operon; a relA + ribosomal product (ppGpp?) may be required for maximal expression. None of the recognized structural genes or their products are required for regulation of trp expression.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
