Gene Symbol: hokC
Description: toxic membrane protein, small
Alias: ECK0018, JW5879, gef
Species: Escherichia coli str. K-12 substr. MG1655

Top Publications

  1. 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...
  2. Poulsen L, Refn A, Molin S, Andersson P. The gef gene from Escherichia coli is regulated at the level of translation. Mol Microbiol. 1991;5:1639-48 pubmed
    We describe post-transcriptional regulation of the chromosomal gene, gef, from Escherichia coli...
  3. Ronchel M, Molina L, Witte A, Lutbiz W, Molin S, Ramos J, et al. Characterization of cell lysis in Pseudomonas putida induced upon expression of heterologous killing genes. Appl Environ Microbiol. 1998;64:4904-11 pubmed
    ..P. putida CMC4 and CMC12 carry in their chromosomes a fusion of the PA1-04/03 promoter to the Escherichia coli gef gene and the phiX174 lysis gene E, respectively...
  4. Gerdes K, Poulsen L, Thisted T, Nielsen A, Martinussen J, Andreasen P. The hok killer gene family in gram-negative bacteria. New Biol. 1990;2:946-56 pubmed
    ..sequenced and include hok/sok from plasmid R1, flm and srnB from plasmid F, pnd from plasmids R483 and R16, and gef and relF, which are located on the Escherichia coli chromosome...
  5. 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. ..
  6. Ronchel M, Ramos J. Dual system to reinforce biological containment of recombinant bacteria designed for rhizoremediation. Appl Environ Microbiol. 2001;67:2649-56 pubmed
    ..g., a porin-inducing protein such as the one encoded by the Escherichia coli gef gene, and a regulatory circuit that controls expression of the killing gene in response to the presence or absence ..
  7. Pedersen K, Gerdes K. Multiple hok genes on the chromosome of Escherichia coli. Mol Microbiol. 1999;32:1090-102 pubmed
    ..e. hokA, hokC and hokE), one system is probably inactivated by point mutation (hokB), whereas the fifth system is inactivated by ..
  8. Boulaiz H, Prados J, Melguizo C, Garcia A, Marchal J, Ramos J, et al. Inhibition of growth and induction of apoptosis in human breast cancer by transfection of gef gene. Br J Cancer. 2003;89:192-8 pubmed
    The gef gene has cell-killing functions in Escherichia coli. To evaluate the feasibility of using this gene as a new strategy for cancer therapy, we transfected it in MCF-7 cells derived from breast cancer (MCF-7TG)...
  9. Jensen L, Ramos J, Kaneva Z, Molin S. A substrate-dependent biological containment system for Pseudomonas putida based on the Escherichia coli gef gene. Appl Environ Microbiol. 1993;59:3713-7 pubmed
    ..One element carries a fusion between a synthetic lac promoter (PA1-04/03) and the gef gene, which encodes a killing function...

More Information


  1. Torensma R, Visser M, Aarsman C, Poppelier M, Fluit A, Verhoef J. Monoclonal antibodies that react with live Listeria spp. Appl Environ Microbiol. 1993;59:2713-6 pubmed
    ..strains, one Escherichia coli strain, and one Citrobacter sp. strain. In Western blots (immunoblots) MAbs 55-23, 55-44, and 34-9 exhibited reactivity; all other MAbs were negative in this assay. ..
  2. Boulaiz H, Prados J, Marchal J, García A, Alvarez L, Melguizo C, et al. Transfection of MS-36 melanoma cells with gef gene inhibits proliferation and induces modulation of the cell cycle. Cancer Sci. 2003;94:564-8 pubmed
    The gef gene, found in Escherichia coli DNA, encodes a small (50 amino acids) protein which is related to cell-killing functions...
  3. Westwater C, Kasman L, Schofield D, Werner P, Dolan J, Schmidt M, et al. Use of genetically engineered phage to deliver antimicrobial agents to bacteria: an alternative therapy for treatment of bacterial infections. Antimicrob Agents Chemother. 2003;47:1301-7 pubmed
    ..concept of using phage as a lethal-agent delivery vehicle, we used the M13 phagemid system and the addiction toxins Gef and ChpBK...
  4. Poulsen L, Refn A, Molin S, Andersson P. Topographic analysis of the toxic Gef protein from Escherichia coli. Mol Microbiol. 1991;5:1627-37 pubmed
    The chromosomal gef gene of Escherichia coli is a member of the gef gene family which encodes strongly toxic proteins of about 50 amino acids. We demonstrate here that the Gef protein is detectable by anti-peptide antibodies...
  5. 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. ..
  6. Sengeløv G, Sørensen S. Methods for detection of conjugative plasmid transfer in aquatic environments. Curr Microbiol. 1998;37:274-80 pubmed
    ..A strain with two copies of the suicide gene gef was successfully eliminated in filter-matings, but elimination of the donor in microcosms by induction of the ..
  7. Lishchenko N, Basnak ian I. [The role of plasmid gef-like genes in eliminating from bacterial populations the specimens that have lost these plasmids]. Zh Mikrobiol Epidemiol Immunobiol. 1997;:90-4 pubmed
  8. Klemm P, Jensen L, Molin S. A stochastic killing system for biological containment of Escherichia coli. Appl Environ Microbiol. 1995;61:481-6 pubmed
    ..located upstream of the fimA gene from Escherichia coli was inserted as expression cassette in front of the lethal gef gene deleted of its own natural promoter. The resulting fusion was placed on a plasmid and transformed to E. coli...
  9. 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
    ..coli lead to collapse of the membrane potential and cell death. A third gene, designated gef, which encodes a homologous cell-toxic protein, has been isolated from E. coli DNA...
  10. Soberón Chávez G. Evaluation of the biological containment system based on the Escherichia coli gef gene in Pseudomonas aeruginosa W51D. Appl Microbiol Biotechnol. 1996;46:549-53 pubmed
    The cell-killing gef gene was introduced, under the control of the lac promoter and as part of a transposon, into Pseudomonas aeruginosa W51D, a strain able to degrade branched-chain alkylbenzene sulfonates...
  11. 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). ..