Characterization of a Novel Toxin-Antitoxin Module, VapBC, Encoded by Leptospira Interrogans Chromosome

Cell Res. 2004 Jun;14(3):208-16. doi: 10.1038/


Comparative genomic analysis of the coding sequences (CDSs) of Leptospira interrogans revealed a pair of closely linked genes homologous to the vapBC loci of many other bacteria with respect to both deduced amino acid sequences and operon organizations. Expression of single vapC gene in Escherichia coli resulted in inhibition of bacterial growth, whereas co-expression of vapBC restored the growth effectively. This phenotype is typical for three other characterized toxin-antitoxin systems of bacteria, i.e., mazEF, relBE and chpIK. The VapC proteins of bacteria and a thermophilic archeae, Solfolobus tokodaii, form a structurally distinguished group of toxin different from the other known toxins of bacteria. Phylogenetic analysis of both toxins and antitoxins of all categories indicated that although toxins were evolved from divergent sources and may or may not follow their speciation paths (as indicated by their 16s RNA sequences), co-evolution with their antitoxins was obvious.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Bacterial Proteins / biosynthesis
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / genetics*
  • Cell Division / genetics
  • Chromosomes, Bacterial / chemistry
  • Chromosomes, Bacterial / genetics*
  • Conserved Sequence
  • DNA-Binding Proteins / biosynthesis
  • DNA-Binding Proteins / chemistry
  • DNA-Binding Proteins / genetics*
  • Escherichia coli / genetics
  • Escherichia coli / growth & development
  • Leptospira interrogans / genetics*
  • Membrane Glycoproteins / biosynthesis
  • Membrane Glycoproteins / chemistry
  • Membrane Glycoproteins / genetics*
  • Molecular Sequence Data
  • Operon / genetics
  • Phylogeny
  • Plasmids / genetics
  • Sequence Homology, Amino Acid


  • Bacterial Proteins
  • DNA-Binding Proteins
  • Membrane Glycoproteins
  • VapB protein, Bacteria