Type II Toxin-Antitoxin Loci: The Epsilon/zeta Family

  • Hannes Mutschler
  • Anton Meinhart


Epsilon/zeta is a widespread TA gene family, members of which stabilise resistance plasmids in Gram-positive and -negative bacteria. Additionally, chromosomally encoded epsilon/zeta loci are virulence determinants in highly pathogenic Streptococcus pneumoniae strains. Here, we provide an overview of the unique mechanism of cell-poisoning by the toxin component, toxin inhibition by antitoxin, regulation of TA protein expression and possible biological functions of this system apart from plasmid maintenance.


Antitoxin Toxin Peptidoglycan Synthesis Stable Inheritance Hypervirulent Strain IncP1 Plasmid 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


  1. Barreteau, H., Kovac, A., Boniface, A., Sova, M., Gobec, S., & Blanot, D. (2008). Cytoplasmic steps of peptidoglycan biosynthesis. FEMS Microbiology Reviews, 32, 168–207.PubMedCrossRefGoogle Scholar
  2. Berry, A. M., & Paton, J. C. (2000). Additive attenuation of virulence of Streptococcus pneumoniae by mutation of the genes encoding pneumolysin and other putative pneumococcal virulence proteins. Infection and Immunity, 68, 133–140.PubMedCrossRefGoogle Scholar
  3. Berry, A. M., Lock, R. A., Hansman, D., & Paton, J. C. (1989a). Contribution of autolysin to virulence of Streptococcus pneumoniae. Infection and Immunity, 57, 2324–2330.PubMedGoogle Scholar
  4. Berry, A. M., Yother, J., Briles, D. E., Hansman, D., & Paton, J. C. (1989b). Reduced virulence of a defined pneumolysin-negative mutant of Streptococcus pneumoniae. Infection and Immunity, 57, 2037–2042.PubMedGoogle Scholar
  5. Bordes, P., Cirinesi, A. M., Ummels, R., Sala, A., Sakr, S., Bitter, W., et al. (2011). SecB-like chaperone controls a toxin–antitoxin stress-responsive system in Mycobacterium tuberculosis. Proceedings of the National Academy of Sciences of the United States of America, 108, 8438–8443.PubMedCrossRefGoogle Scholar
  6. Brantl, S., Behnke, D., & Alonso, J. C. (1990). Molecular analysis of the replication region of the conjugative Streptococcus agalactiae plasmid pIP501 in Bacillus subtilis. Comparison with plasmids pAM beta 1 and pSM19035. Nucleic Acids Research, 18, 4783–4790.PubMedCrossRefGoogle Scholar
  7. Braun, J. S., Sublett, J. E., Freyer, D., Mitchell, T. J., Cleveland, J. L., Tuomanen, E. I., et al. (2002). Pneumococcal pneumolysin and H(2)O(2) mediate brain cell apoptosis during meningitis. The Journal of Clinical Investigation, 109, 19–27.PubMedGoogle Scholar
  8. Brown, J. S., Gilliland, S. M., & Holden, D. W. (2001). A Streptococcus pneumoniae pathogenicity island encoding an ABC transporter involved in iron uptake and virulence. Molecular Microbiology, 40, 572–585.PubMedCrossRefGoogle Scholar
  9. Brown, J. S., Gilliland, S. M., Spratt, B. G., & Holden, D. W. (2004). A locus contained within a variable region of pneumococcal pathogenicity island 1 contributes to virulence in mice. Infection and Immunity, 72, 1587–1593.PubMedCrossRefGoogle Scholar
  10. Brzozowska, I., Brzozowska, K., Zielenkiewicz, U. (2012). Functioning of the TA cassette of streptococcal plasmid pSM19035 in various Gram-positive bacteria. Plasmid, 68, 51–60.Google Scholar
  11. Camacho, A. G., Misselwitz, R., Behlke, J., Ayora, S., Welfle, K., Meinhart, A., et al. (2002). In vitro and in vivo stability of the ε 2 ζ 2 protein complex of the broad host-range Streptococcus pyogenes pSM19035 addiction system. Biological Chemistry, 383, 1701–1713.PubMedCrossRefGoogle Scholar
  12. Ceglowski, P., Boitsov, A., Chai, S., & Alonso, J. C. (1993a). Analysis of the stabilization system of pSM19035-derived plasmid pBT233 in Bacillus subtilis. Gene, 136, 1–12.PubMedCrossRefGoogle Scholar
  13. Ceglowski, P., Boitsov, A., Karamyan, N., Chai, S., & Alonso, J. C. (1993b). Characterization of the effectors required for stable inheritance of Streptococcus pyogenes pSM19035-derived plasmids in Bacillus subtilis. Molecular Genetics and Genomics, 241, 579–585.Google Scholar
  14. Christensen, S. K., Pedersen, K., Hansen, F. G., & Gerdes, K. (2003). Toxin–antitoxin loci as stress-response-elements: ChpAK/MazF and ChpBK cleave translated RNAs and are counteracted by tmRNA. Journal of Molecular Biology, 332, 809–819.PubMedCrossRefGoogle Scholar
  15. Clewell, D. B. (1981). Plasmids, drug resistance, and gene transfer in the genus Streptococcus. Microbiological Reviews, 45, 409–436.PubMedGoogle Scholar
  16. Cockeran, R., Theron, A. J., Steel, H. C., Matlola, N. M., Mitchell, T. J., Feldman, C., et al. (2001). Proinflammatory interactions of pneumolysin with human neutrophils. Journal of Infectious Diseases, 183, 604–611.PubMedCrossRefGoogle Scholar
  17. Croucher, N. J., Walker, D., Romero, P., Lennard, N., Paterson, G. K., Bason, N. C., et al. (2009). Role of conjugative elements in the evolution of the multidrug-resistant pandemic clone Streptococcus pneumoniae Spain23F ST81. Journal of Bacteriology, 191, 1480–1489.PubMedCrossRefGoogle Scholar
  18. de la Hoz, A. B., Ayora, S., Sitkiewicz, I., Fernandez, S., Pankiewicz, R., Alonso, J. C., et al. (2000). Plasmid copy-number control and better-than-random segregation genes of pSM19035 share a common regulator. Proceedings of the National Academy of Sciences of the United States of America, 97, 728–733.PubMedCrossRefGoogle Scholar
  19. Dixon, J. M., & Lipinski, A. E. (1972). Resistance of group A beta-hemolytic streptococci to lincomycin and erythromycin. Antimicrobial Agents and Chemotherapy, 1, 333–339.PubMedCrossRefGoogle Scholar
  20. Du, W., Brown, J. R., Sylvester, D. R., Huang, J., Chalker, A. F., So, C. Y., et al. (2000). Two active forms of UDP-N-acetylglucosamine enolpyruvyl transferase in Gram-positive bacteria. Journal of Bacteriology, 182, 4146–4152.PubMedCrossRefGoogle Scholar
  21. Garcia-Pino, A., Balasubramanian, S., Wyns, L., Gazit, E., De Greve, H., Magnuson, R. D., et al. (2010). Allostery and intrinsic disorder mediate transcription regulation by conditional cooperativity. Cell, 142, 101–111.PubMedCrossRefGoogle Scholar
  22. Gilbert, R. J., Jimenez, J. L., Chen, S., Tickle, I. J., Rossjohn, J., Parker, M., et al. (1999). Two structural transitions in membrane pore formation by pneumolysin, the pore-forming toxin of Streptococcus pneumoniae. Cell, 97, 647–655.PubMedCrossRefGoogle Scholar
  23. Guiral, S., Mitchell, T. J., Martin, B., & Claverys, J. P. (2005). Competence-programmed predation of noncompetent cells in the human pathogen Streptococcus pneumoniae: Genetic requirements. Proceedings of the National Academy of Sciences of the United States of America, 102, 8710–8715.PubMedCrossRefGoogle Scholar
  24. Harvey, R. M., Stroeher, U. H., Ogunniyi, A. D., Smith-Vaughan, H. C., Leach, A. J., & Paton, J. C. (2011). A variable region within the genome of Streptococcus pneumoniae contributes to strain–strain variation in virulence. PLoS ONE, 6, e19650.PubMedCrossRefGoogle Scholar
  25. Hirst, R. A., Kadioglu, A., O’Callaghan, C., & Andrew, P. W. (2004). The role of pneumolysin in pneumococcal pneumonia and meningitis. Clinical and Experimental Immunology, 138, 195–201.PubMedCrossRefGoogle Scholar
  26. Holden, M. T., Hauser, H., Sanders, M., Ngo, T. H., Cherevach, I., Cronin, A., et al. (2009). Rapid evolution of virulence and drug resistance in the emerging zoonotic pathogen Streptococcus suis. PLoS ONE, 4, e6072.PubMedCrossRefGoogle Scholar
  27. Khoo, S. K., Loll, B., Chan, W. T., Shoeman, R. L., Ngoo, L., Yeo, C. C., et al. (2007). Molecular and structural characterization of the PezAT chromosomal toxin–antitoxin system of the human pathogen Streptococcus pneumoniae. Journal of Biological Chemistry, 282, 19606–19618.PubMedCrossRefGoogle Scholar
  28. Leipe, D. D., Koonin, E. V., & Aravind, L. (2003). Evolution and classification of P-loop kinases and related proteins. Journal of Molecular Biology, 333, 781–815.PubMedCrossRefGoogle Scholar
  29. Leplae, R., Geeraerts, D., Hallez, R., Guglielmini, J., Dreze, P., & Van Melderen, L. (2011). Diversity of bacterial type II toxin–antitoxin systems: A comprehensive search and functional analysis of novel families. Nucleic Acids Research, 39, 5513–5525.PubMedCrossRefGoogle Scholar
  30. Lioy, V. S., Martin, M. T., Camacho, A. G., Lurz, R., Antelmann, H., Hecker, M., et al. (2006). pSM19035-encoded zeta toxin induces stasis followed by death in a subpopulation of cells. Microbiology, 152, 2365–2379.PubMedCrossRefGoogle Scholar
  31. Lioy, V. S., Pratto, F., de la Hoz, A. B., Ayora, S., & Alonso, J. C. (2010). Plasmid pSM19035, a model to study stable maintenance in firmicutes. Plasmid, 64, 1–17.PubMedCrossRefGoogle Scholar
  32. Lioy, V. S., Machon, C., Tabone, M., Gonzalez-Pastor, J. E., Daugelavicius, R., Ayora, S., et al. (2012). The zeta toxin induces a set of protective responses and dormancy. PLoS ONE, 7, e30282.PubMedCrossRefGoogle Scholar
  33. Lock, R. A., Hansman, D., & Paton, J. C. (1992). Comparative efficacy of autolysin and pneumolysin as immunogens protecting mice against infection by Streptococcus pneumoniae. Microbial Pathogenesis, 12, 137–143.PubMedCrossRefGoogle Scholar
  34. Martner, A., Dahlgren, C., Paton, J. C., & Wold, A. E. (2008). Pneumolysin released during Streptococcus pneumoniae autolysis is a potent activator of intracellular oxygen radical production in neutrophils. Infection and Immunity, 76, 4079–4087.PubMedCrossRefGoogle Scholar
  35. Martner, A., Skovbjerg, S., Paton, J. C., & Wold, A. E. (2009). Streptococcus pneumoniae autolysis prevents phagocytosis and production of phagocyte-activating cytokines. Infection and Immunity, 77, 3826–3837.PubMedCrossRefGoogle Scholar
  36. Meinhart, A., Alings, C., Strater, N., Camacho, A. G., Alonso, J. C., & Saenger, W. (2001). Crystallization and preliminary X-ray diffraction studies of the εζ addiction system encoded by Streptococcus pyogenes plasmid pSM19035. Acta Crystallographica. Section D, Biological Crystallography, 57, 745–747.PubMedCrossRefGoogle Scholar
  37. Meinhart, A., Alonso, J. C., Strater, N., & Saenger, W. (2003). Crystal structure of the plasmid maintenance system ε/ζ: Functional mechanism of toxin ζ and inactivation by ε 2 ζ 2 complex formation. Proceedings of the National Academy of Sciences of the United States of America, 100, 1661–1666.PubMedCrossRefGoogle Scholar
  38. Mitchell, T. J., Andrew, P. W., Saunders, F. K., Smith, A. N., & Boulnois, G. J. (1991). Complement activation and antibody binding by pneumolysin via a region of the toxin homologous to a human acute-phase protein. Molecular Microbiology, 5, 1883–1888.PubMedCrossRefGoogle Scholar
  39. Murayama, K., Orth, P., de la Hoz, A. B., Alonso, J. C., & Saenger, W. (2001). Crystal structure of omega transcriptional repressor encoded by Streptococcus pyogenes plasmid pSM19035 at 1.5 Å resolution. Journal of Molecular Biology, 314, 789–796.PubMedCrossRefGoogle Scholar
  40. Mutschler, H., & Meinhart, A. (2011). Epsilon/zeta systems: Their role in resistance, virulence, and their potential for antibiotic development. Journal of Molecular Medicine, 89, 1183–1194.PubMedCrossRefGoogle Scholar
  41. Mutschler, H., Reinstein, J., & Meinhart, A. (2010). Assembly dynamics and stability of the pneumococcal epsilon zeta antitoxin toxin (PezAT) system from Streptococcus pneumoniae. Journal of Biological Chemistry, 285, 21797–21806.PubMedCrossRefGoogle Scholar
  42. Mutschler, H., Gebhardt, M., Shoeman, R. L., & Meinhart, A. (2011). A novel mechanism of programmed cell death in bacteria by toxin–antitoxin systems corrupts peptidoglycan synthesis. PLoS Biology, 9, e1001033.PubMedCrossRefGoogle Scholar
  43. Nau, R., & Eiffert, H. (2002). Modulation of release of proinflammatory bacterial compounds by antibacterials: Potential impact on course of inflammation and outcome in sepsis and meningitis. Clinical Microbiology Reviews, 15, 95–110.PubMedCrossRefGoogle Scholar
  44. Nowakowska, B., Kern-Zdanowicz, I., Zielenkiewicz, U., & Ceglowski, P. (2005). Characterization of Bacillus subtilis clones surviving overproduction of Zeta, a pSM19035 plasmid-encoded toxin. Acta Biochimica Polonica, 52, 99–107.PubMedGoogle Scholar
  45. Overgaard, M., Borch, J., Jorgensen, M. G., & Gerdes, K. (2008). Messenger RNA interferase RelE controls relBE transcription by conditional cooperativity. Molecular Microbiology, 69, 841–857.PubMedCrossRefGoogle Scholar
  46. Pachulec, E., & van der Does, C. (2010). Conjugative plasmids of Neisseria gonorrhoeae. PLoS ONE, 5, e9962.PubMedCrossRefGoogle Scholar
  47. Pinas, G. E., Cortes, P. R., Orio, A. G., & Echenique, J. (2008). Acidic stress induces autolysis by a CSP-independent ComE pathway in Streptococcus pneumoniae. Microbiology, 154, 1300–1308.PubMedCrossRefGoogle Scholar
  48. Pratto, F., Cicek, A., Weihofen, W. A., Lurz, R., Saenger, W., & Alonso, J. C. (2008). Streptococcus pyogenes pSM19035 requires dynamic assembly of ATP-bound ParA and ParB on parS DNA during plasmid segregation. Nucleic Acids Research, 36, 3676–3689.PubMedCrossRefGoogle Scholar
  49. Ramage, H. R., Connolly, L. E., & Cox, J. S. (2009). Comprehensive functional analysis of Mycobacterium tuberculosis toxin–antitoxin systems: Implications for pathogenesis, stress responses, and evolution. PLoS Genetics, 5, e1000767.PubMedCrossRefGoogle Scholar
  50. Regev-Yochay, G., Trzcinski, K., Thompson, C. M., Lipsitch, M., & Malley, R. (2007). SpxB is a suicide gene of Streptococcus pneumoniae and confers a selective advantage in an in vivo competitive colonization model. Journal of Bacteriology, 189, 6532–6539.PubMedCrossRefGoogle Scholar
  51. Rosvoll, T. C., Pedersen, T., Sletvold, H., Johnsen, P. J., Sollid, J. E., Simonsen, G. S., et al. (2010). PCR-based plasmid typing in Enterococcus faecium strains reveals widely distributed pRE25-, pRUM-, pIP501- and pHTbeta-related replicons associated with glycopeptide resistance and stabilizing toxin–antitoxin systems. FEMS Immunology and Medical Microbiology, 58, 254–268.PubMedCrossRefGoogle Scholar
  52. Schlesinger, D. J., Shoemaker, N. B., & Salyers, A. A. (2007). Possible origins of CTnBST, a conjugative transposon found recently in a human colonic Bacteroides strain. Applied and Environment Microbiology, 73, 4226–4233.CrossRefGoogle Scholar
  53. Schwarz, F. V., Perreten, V., & Teuber, M. (2001). Sequence of the 50-kb conjugative multiresistance plasmid pRE25 from Enterococcus faecalis RE25. Plasmid, 46, 170–187.PubMedCrossRefGoogle Scholar
  54. Sletvold, H., Johnsen, P. J., Simonsen, G. S., Aasnaes, B., Sundsfjord, A., & Nielsen, K. M. (2007). Comparative DNA analysis of two vanA plasmids from Enterococcus faecium strains isolated from poultry and a poultry farmer in Norway. Antimicrobial Agents and Chemotherapy, 51, 736–739.PubMedCrossRefGoogle Scholar
  55. Sletvold, H., Johnsen, P. J., Hamre, I., Simonsen, G. S., Sundsfjord, A., & Nielsen, K. M. (2008). Complete sequence of Enterococcus faecium pVEF3 and the detection of an omega-epsilon-zeta toxin–antitoxin module and an ABC transporter. Plasmid, 60, 75–85.PubMedCrossRefGoogle Scholar
  56. Tettelin, H., Nelson, K. E., Paulsen, I. T., Eisen, J. A., Read, T. D., Peterson, S., et al. (2001). Complete genome sequence of a virulent isolate of Streptococcus pneumoniae. Science, 293, 498–506.PubMedCrossRefGoogle Scholar
  57. Van Melderen, L., & Saavedra De Bast, M. (2009). Bacterial toxin–antitoxin systems: More than selfish entities? PLoS Genetics, 5, e1000437.PubMedCrossRefGoogle Scholar
  58. Wang, X., Kim, Y., Hong, S. H., Ma, Q., Brown, B. L., Pu, M., et al. (2011). Antitoxin MqsA helps mediate the bacterial general stress response. Nature Chemical Biology, 7, 359–366.PubMedCrossRefGoogle Scholar
  59. Weihofen, W. A., Cicek, A., Pratto, F., Alonso, J. C., & Saenger, W. (2006). Structures of omega repressors bound to direct and inverted DNA repeats explain modulation of transcription. Nucleic Acids Research, 34, 1450–1458.PubMedCrossRefGoogle Scholar
  60. Winther, K. S., & Gerdes, K. (2012). Regulation of enteric vapBC transcription: Induction by VapC toxin dimer-breaking. Nucleic Acids Research, 40, 4347–4357.PubMedCrossRefGoogle Scholar
  61. Zielenkiewicz, U., & Ceglowski, P. (2001). Mechanisms of plasmid stable maintenance with special focus on plasmid addiction systems. Acta Biochimica Polonica, 48, 1003–1023.PubMedGoogle Scholar
  62. Zielenkiewicz, U., & Ceglowski, P. (2005). The toxin–antitoxin system of the streptococcal plasmid pSM19035. Journal of Bacteriology, 187, 6094–6105.PubMedCrossRefGoogle Scholar

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© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  1. 1.Department of Biomolecular MechanismsMax Planck Institute for Medical ResearchHeidelbergGermany

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