Skip to Main content Skip to Navigation
Journal articles

Environmental Response and Autoregulation of Clostridium difficile TxeR, a Sigma Factor for Toxin Gene Expression

Abstract : TxeR, a sigma factor that directs Clostridium difficile RNA polymerase to recognize the promoters of two major toxin genes, was shown to stimulate its own synthesis. Whether expressed in C. difficile, Clostridium perfringens, or Escherichia coli, TxeR stimulated transcription of fusions of the txeR promoter region to reporter genes. As is the case for the tox genes, txeR expression was responsive to the cellular growth phase and the constituents of the medium. That is, the level of expression in broth culture was low during the exponential growth phase, but rapidly increased as cells approached the stationary phase. In the presence of excess glucose, expression from the txeR promoter was repressed. The results support a model for toxin gene expression in which synthesis of TxeR is induced by specific environmental signals. The increased level of TxeR then permits high-level expression of the toxin genes. The study of txeR gene regulation in C. difficile was made possible by introduction of a mobilizable, replicative plasmid via conjugation with E. coli.
Complete list of metadatas

https://hal-pasteur.archives-ouvertes.fr/pasteur-02445952
Contributor : Nadine Delarue <>
Submitted on : Monday, January 20, 2020 - 3:04:38 PM
Last modification on : Tuesday, January 21, 2020 - 2:51:02 PM

Links full text

Identifiers

Collections

Citation

N. Mani, D. Lyras, L. Barroso, P. Howarth, T. Wilkins, et al.. Environmental Response and Autoregulation of Clostridium difficile TxeR, a Sigma Factor for Toxin Gene Expression. Journal of Bacteriology, American Society for Microbiology, 2002, 184 (21), pp.5971-5978. ⟨10.1128/jb.184.21.5971-5978.2002⟩. ⟨pasteur-02445952⟩

Share

Metrics

Record views

40