The iron-dependent repressor YtgR is a tryptophan-dependent attenuator of the trpRBA operon in Chlamydia trachomatis.

ABSTRACT: The trp operon of Chlamydia trachomatis is organized differently from other model bacteria. It contains trpR, an intergenic region (IGR), and the biosynthetic trpB and trpA open-reading frames. TrpR is a tryptophan-dependent repressor that regulates the major promoter (P_trpR), while the IGR harbors an alternative promoter (P_trpBA) and an operator sequence for the iron-dependent repressor YtgR to regulate trpBA expression. Here, we report that YtgR repression at P_trpBA is also dependent on tryptophan by regulating YtgR levels through a rare triple-tryptophan motif (WWW) in the YtgCR precursor. Inhibiting translation during tryptophan limitation at the WWW motif subsequently promotes Rho-independent transcription termination of ytgR, thereby de-repressing P

SUBMITTER: Pokorzynski ND 

PROVIDER: S-EPMC7755916 | biostudies-literature | 2020 Dec

REPOSITORIES: biostudies-literature