Trp repressor (IPR000831)

Short name: Trp_repress

Overlapping homologous superfamilies

Family relationships


The Trp repressor (TrpR) binds to at least five operators in the Escherichia coli genome, repressing gene expression. The operators at which it binds vary considerably in DNA sequence and location within the promoter; when bound to the Trp operon it recognises the sequence 5'-ACTAGT-3' and acts to prevent the initiation of transcription. The TrpR controls the trpEDCBA (trpO) operon and the genes for trpR, aroH, mtr and aroL, which are involved in the biosynthesis and uptake of the amino acid tryptophan [PMID: 12475235]. The repressor binds to the operators only in the presence of L-tryptophan, thereby controlling the intracellular level of its effector; the complex also regulates Trp repressor biosynthesis by binding to its own regulatory region. TrpR acts as a dimer that is composed of identical 6-helical subunits, where four of the helices form the core of the protein and intertwine with the corresponding helices from the other subunit.

GO terms

Biological Process

GO:0006355 regulation of transcription, DNA-templated

Molecular Function

GO:0003700 DNA-binding transcription factor activity

Cellular Component

GO:0005622 intracellular

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.