Biochemical Characterization of a Chromosomal Toxin-Antitoxin System in Mycobacterium Tuberculosis

FEBS Lett. 2008 Mar 5;582(5):710-4. doi: 10.1016/j.febslet.2008.01.045. Epub 2008 Feb 5.


In the present paper, we report the biochemical characterization of a chromosomal toxin-antitoxin (TA) system in Mycobacterium tuberculosis, consisting of the Rv1991c gene and its upstream open reading frame (ORF) termed Rv1991a. Rv1991c was characterized as a toxin with ribonuclease activity and Rv1991a as the antitoxin against Rv1991c. Rv1991a interacted with Rv1991c to form a complex. A promoter located immediately upstream of Rv1991a was identified. Both Rv1991a and the Rv1991a-Rv1991c complex were able to bind to the promoter region of the Rv1991a-Rv1991c operon, indicating that the expression of the Rv1991a-Rv1991c operon can be autoregulated.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antitoxins / metabolism*
  • Bacterial Proteins / metabolism
  • Bacterial Toxins / metabolism*
  • Chromosomes, Bacterial / metabolism*
  • DNA, Bacterial / metabolism
  • Mycobacterium tuberculosis / enzymology
  • Mycobacterium tuberculosis / metabolism*
  • Promoter Regions, Genetic / genetics
  • Protein Binding
  • Ribonucleases / metabolism*


  • Antitoxins
  • Bacterial Proteins
  • Bacterial Toxins
  • DNA, Bacterial
  • Ribonucleases