Autoprocessing of the Vibrio cholerae RTX toxin by the cysteine protease domain

Kerri Lynn Sheahan, Christina L. Cordero, Karla J.Fullner Satchell*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

81 Scopus citations


Vibrio cholerae RTX is a large multifunctional bacterial toxin that causes actin crosslinking. Due to its size, it was predicted to undergo proteolytic cleavage during translocation into host cells to deliver activity domains to the cytosol. In this study, we identified a domain within the RTX toxin that is conserved in large clostridial glucosylating toxins TcdB, TcdA, TcnA, and TcsL; putative toxins from V. vulnificus, Yersinia sp., Photorhabdus sp., and Xenorhabdus sp.; and a filamentous/hemagglutinin-like protein FhaL from Bordetella sp. In vivo transfection studies and in vitro characterization of purified recombinant protein revealed that this domain from the V. cholerae RTX toxin is an autoprocessing cysteine protease whose activity is stimulated by the intracellular environment. A cysteine point mutation within the RTX holotoxin attenuated actin crosslinking activity suggesting that processing of the toxin is an important step in toxin translocation. Overall, we have uncovered a new mechanism by which large bacterial toxins and proteins deliver catalytic activities to the eukaryotic cell cytosol by autoprocessing after translocation.

Original languageEnglish (US)
Pages (from-to)2552-2561
Number of pages10
JournalEMBO Journal
Issue number10
StatePublished - May 16 2007


  • Clostridium difficile Toxin B
  • Cysteine protease
  • GTP
  • HCV NS2
  • V. cholerae RTX toxin

ASJC Scopus subject areas

  • General Immunology and Microbiology
  • General Biochemistry, Genetics and Molecular Biology
  • Molecular Biology
  • General Neuroscience


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