Gene Symbol: hokD
Description: Qin prophage; small toxic polypeptide
Alias: ECK1556, JW1554, relF
Species: Escherichia coli str. K-12 substr. MG1655

Top Publications

  1. Gerdes K, Bech F, Jørgensen S, Løbner Olesen A, Rasmussen P, Atlung T, et al. Mechanism of postsegregational killing by the hok gene product of the parB system of plasmid R1 and its homology with the relF gene product of the E. coli relB operon. EMBO J. 1986;5:2023-9 pubmed
    ..A gene located in the Escherichia coli relB operon, designated relF, is shown to be homologous to the hok gene...
  2. Gerdes K, Gultyaev A, Franch T, Pedersen K, Mikkelsen N. Antisense RNA-regulated programmed cell death. Annu Rev Genet. 1997;31:1-31 pubmed
    ..The complex phylogenetic relationships of the plasmid- and chromosome-encoded systems are also presented and discussed. ..
  3. Pedersen K, Gerdes K. Multiple hok genes on the chromosome of Escherichia coli. Mol Microbiol. 1999;32:1090-102 pubmed
    ..inactivated by point mutation (hokB), whereas the fifth system is inactivated by a major genetic rearrangement (hokD). In the ECOR collection of wild-type E. coli strains, we identified hokA and hokC loci without IS elements...
  4. Knudsen S, Karlström O. Development of efficient suicide mechanisms for biological containment of bacteria. Appl Environ Microbiol. 1991;57:85-92 pubmed
    ..we have systematically investigated the factors that limit the killing efficiency of a suicide system based on the relF gene from Escherichia coli controlled by inducible lac promoters and placed on plasmids...
  5. Poulsen L, Larsen N, Molin S, Andersson P. A family of genes encoding a cell-killing function may be conserved in all gram-negative bacteria. Mol Microbiol. 1989;3:1463-72 pubmed
    The relF gene in Escherichia coli is related to the hok gene on plasmid R1. Both genes encode small proteins which, when overexpressed in E. coli lead to collapse of the membrane potential and cell death...
  6. Bech F, Jørgensen S, Diderichsen B, Karlström O. Sequence of the relB transcription unit from Escherichia coli and identification of the relB gene. EMBO J. 1985;4:1059-66 pubmed
    ..By nuclease S1 mapping we have determined the transcription start and stop of an 870 base transcript of the relB gene. ..
  7. Knudsen S, Saadbye P, Hansen L, Collier A, Jacobsen B, Schlundt J, et al. Development and testing of improved suicide functions for biological containment of bacteria. Appl Environ Microbiol. 1995;61:985-91 pubmed
    We have developed very efficient suicide functions for biological containment based on the lethal Escherichia coli relF gene...
  8. Hayes F. A family of stability determinants in pathogenic bacteria. J Bacteriol. 1998;180:6415-8 pubmed
    ..coli. Furthermore, the stbDE genes share homology with components of the relBEF operon and with the dnaT gene of E. coli. The organization of the stbDE cassette is reminiscent of toxin-antitoxin stability cassettes...
  9. Faridani O, Nikravesh A, Pandey D, Gerdes K, Good L. Competitive inhibition of natural antisense Sok-RNA interactions activates Hok-mediated cell killing in Escherichia coli. Nucleic Acids Res. 2006;34:5915-22 pubmed
    ..Therefore, it is possible to activate suicide in bacteria by targeting antitoxins. ..

More Information


  1. Gerdes K, Wagner E. RNA antitoxins. Curr Opin Microbiol. 2007;10:117-24 pubmed
    ..Thus, it is possible that an ancestral antitoxin gene evolved into the present toxin gene (symE) whose translation is repressed by an RNA antitoxin (SymR). ..
  2. Poulsen L, Larsen N, Molin S, Andersson P. Analysis of an Escherichia coli mutant strain resistant to the cell-killing function encoded by the gef gene family. Mol Microbiol. 1992;6:895-905 pubmed
    The chromosomal genes gef and relF from Escherichia coli and the plasmid-encoded genes hok, flmA, srnB, and pndA constitute the gef gene family, which encodes a cell-killing function...