| Trp repressor protein | |||||||||
|---|---|---|---|---|---|---|---|---|---|
 Ribbon diagram of the trpR protein | |||||||||
| Identifiers | |||||||||
| Symbol | Trp_repressor | ||||||||
| Pfam | PF01371 | ||||||||
| Pfam clan | CL0123 | ||||||||
| InterPro | IPR000831 | ||||||||
| SCOP2 | 2wrp / SCOPe / SUPFAM | ||||||||
| |||||||||
| Trp operon repressor | |||||||
|---|---|---|---|---|---|---|---|
| Identifiers | |||||||
| Organism | |||||||
| Symbol | trpR | ||||||
| Entrez | 948917 | ||||||
| RefSeq (Prot) | NP_418810 | ||||||
| UniProt | P0A881 | ||||||
| Other data | |||||||
| Chromosome | genome: 4.63 - 4.63 Mb | ||||||
| |||||||
Tryptophan repressor (or trp repressor) is a transcription factor involved in controlling amino acid metabolism. It has been best studied in Escherichia coli, where it is a dimeric protein that regulates transcription of the 5 genes in the tryptophan operon.[1] When the amino acid tryptophan is plentiful in the cell, it binds to the protein, which causes a conformational change in the protein.[2] The repressor complex then binds to its operator sequence in the genes it regulates, shutting off the genes.[3][4]
One of the genes regulated by trp repressor, trpR, codes for the tryptophan repressor protein itself. This is a form of feedback regulation. However, these genes are located on different operons.
The (tryptophan) repressor is a 25 kD protein homodimer which regulates transcription of the tryptophan biosynthetic pathway in bacteria. There are 5 operons which are regulated by trpR: the trpEDCBA, trpR, AroH, AroL, and mtr operons.
- ^ Santillan M, Mackey MC (2001). "Dynamic regulation of the tryptophan operon: A modeling study and comparison with experimental data". Proc. Natl. Acad. Sci. U.S.A. 98 (4): 1364–9. Bibcode:2001PNAS...98.1364S. doi:10.1073/pnas.98.4.1364. PMC 29262. PMID 11171956.
- ^ Zhang RG, Joachimiak A, Lawson CL, Schevitz RW, Otwinowski Z, Sigler PB (1987). "The crystal structure of trp aporepressor at 1.8 A shows how binding tryptophan enhances DNA affinity". Nature. 327 (6123): 591–7. Bibcode:1987Natur.327..591Z. doi:10.1038/327591a0. PMID 3600756. S2CID 4335349.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Jeeves M, Evans PD, Parslow RA, Jaseja M, Hyde EI (1999). "Studies of the Escherichia coli Trp repressor binding to its five operators and to variant operator sequences". Eur. J. Biochem. 265 (3): 919–28. doi:10.1046/j.1432-1327.1999.00792.x. PMID 10518785.
- ^ Arvidson DN, Arvidson CG, Lawson CL, Miner J, Adams C, Youderian P (1994). "The tryptophan repressor sequence is highly conserved among the Enterobacteriaceae". Nucleic Acids Res. 22 (10): 1821–9. doi:10.1093/nar/22.10.1821. PMC 308080. PMID 8208606.