Stealth and mimicry by deadly bacterial toxins

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Susan P Yates1, René Jørgensen, Gregers R Andersen

  • 1Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada.

Trends in Biochemical Sciences
|January 13, 2006
PubMed

Insights

ADP-ribosyltransferase toxins, like diphtheria toxin and exotoxin A, inactivate protein synthesis. New structural and kinetic data reveal their stealthy molecular mimicry strategy in host cells.

Area of Science:

  • Biochemistry
  • Molecular Biology
  • Microbiology

Background:

  • Diphtheria toxin and exotoxin A are virulence factors from pathogenic bacteria.
  • These toxins belong to the ADP-ribosyltransferase family.
  • They inhibit protein synthesis in host eukaryotic cells.

Purpose of the Study:

  • To elucidate the mechanism of protein synthesis inactivation by ADP-ribosyltransferase toxins.
  • To gain insights into the molecular strategy employed by these toxins.

Main Methods:

  • High-resolution structural analysis of the enzyme-substrate complex.
  • Steady-state and stopped-flow kinetic analyses.
  • Inhibitor studies.

Main Results:

  • Detailed mechanistic insights into the toxin-catalyzed reaction.
  • Understanding of the enzyme-substrate interactions.
  • Revealed the use of molecular mimicry and stealth by the toxins.

Conclusions:

  • The study provides a quantum leap in understanding the deadly enzyme mechanism of ADP-ribosyltransferases.
  • These toxins employ sophisticated strategies, including molecular mimicry, to target host cells.
  • The findings enhance our knowledge of bacterial virulence factors.

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