Coding

Part:BBa_K4604011

Designed by: Hannah Swientek   Group: iGEM23_Freiburg   (2023-09-30)


MazF toxin

In this BioBrick we fused MazF together with a FLAG-tag using a 3X Alanine linker. This FLAG-tag can be used for protein detection via western blot. Also used in BioBricks BBa_K4604017, BBa_K4604018, BBa_K4604019, BBa_K4604021, BBa_K4604022, BBa_K4604023, BBa_K4604024and BBa_K4604025. See more about the explicit functionality of the toxin under BBa_K4604024.


Usage and Biology

Toxin-antitoxin systems (TA-systems) play a crucial role in plasmid stability for naturally occurring plasmids [1]. Usually, the toxin targets essential cellular functions and causes growth arrest or cell death, to which the antitoxin acts as a counterpart. Toxin and antitoxin exhibit differences in their stability and lifespan [2]. While the antitoxin has a shortened lifespan due to its sensitivity to degradation, the toxin has a longer lifespan and is more stable. If the plasmid that contains the TA-system is lost, the antitoxin is rapidly degraded and the toxin concentration increases, leading to cell death. Therefore, when first discovered, TA systems were called “addiction modules” that ensure plasmid retention. The labile MazE (antitoxin) acts as a neutralizer to the stable MazF (toxin), which acts as an endoribonuclease. When MazF is present freely in the cell it cuts cellular RNA which ultimately leads to cell death.


Figure 1: 3D structure of MazE/MazF hexamer. Pdb file was taken from the Protein Data Bank, display was done with Molstar.


Sequence and Features


Assembly Compatibility:
  • 10
    COMPATIBLE WITH RFC[10]
  • 12
    COMPATIBLE WITH RFC[12]
  • 21
    COMPATIBLE WITH RFC[21]
  • 23
    COMPATIBLE WITH RFC[23]
  • 25
    COMPATIBLE WITH RFC[25]
  • 1000
    COMPATIBLE WITH RFC[1000]



References

[1]Ni S, Li B, Tang K, Yao J, Wood TK, Wang P, et al. Conjugative plasmid-encoded toxin–antitoxin system PrpT/PrpA directly controls plasmid copy number. Proceedings of the National Academy of Sciences of the United States of America [Internet]. 2021 Jan 22;118(4). Available from: https://doi.org/10.1073/pnas.2011577118

[2]Brzozowska I, Zielenkiewicz U. Regulation of toxin–antitoxin systems by proteolysis. Plasmid [Internet]. 2013 Jul 1;70(1):33–41. Available from: https://doi.org/10.1016/j.plasmid.2013.01.007

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