T-box

The T-box element is an RNA switch that controls genes involved in amino acid metabolism.

In the absence of an amino acid, the uncharged tRNA binds the T-box region in the leader region of the mRNA of the controlled gene/ operon and thereby prevents the formation of a transcription terminator. The result is gene expression of the target gene in the absence of the specific amino acid.

Complete list of genes controlled by T-box elements

• Induction by alanine limitation
  • alaS

• Induction by aspartate limitation
  • hisS-aspS

• Induction by cysteine limitation
  • cysE-cysS-mrnC-yacO-yacP

• Induction by glycine limitation
  • glyA, glyQ-glyS

• Induction by histidine limitation
  • hisS-aspS

• Induction by isoleucine limitation
  • ileS, ilvB-ilvH-ilvC-leuA-leuA-leuC-leuD

• Induction by leucine limitation
  • leuS, ilvB-ilvH-ilvC-leuA-leuA-leuC-leuD, yvbW

• Induction by phenyalanine limitation
  • pheS-pheT

• Induction by proline limitation
  • proB-proA, proI

• Induction by serine limitation
  • serS

• Induction by threonine limitation
  • thrS, thrZ-ywhA

• Induction by tryptophan limitation
  • rtpA-ycbK, trpS

• Induction by tyrosine limitation
  • tyrS, tyrZ

• Induction by valine limitation
  • valS, ilvB-ilvH-ilvC-leuA-leuA-leuC-leuD

Structure of a T-box ribowsitch

Xianyang Fang, Malgorzata Michnicka, Yikan Zhang, Yun-Xing Wang, Edward P Nikonowicz
Capture and Release of tRNA by the T-Loop Receptor in the Function of the T-Box Riboswitch.
Biochemistry: 2017, 56(28);3549-3558
[PubMed:28621923] [WorldCat.org] [DOI] (I p)

Melinda S Gerdeman, Tina M Henkin, Jennifer V Hines
Solution structure of the Bacillus subtilis T-box antiterminator RNA: seven nucleotide bulge characterized by stacking and flexibility.
J Mol Biol: 2003, 326(1);189-201
[PubMed:12547201] [WorldCat.org] [DOI] (P p)

See also:

• RNA switch