Conjugative plasmid-encoded toxin–antitoxin system PrpT/PrpA directly controls plasmid copy number

  • Songwei Ni, Baiyuan Li, Kaihao Tang, Jianyun Yao, Thomas K. Wood, Pengxia Wang, Xiaoxue Wang
  • Proceedings of the National Academy of Sciences, January 2021, Proceedings of the National Academy of Sciences
  • DOI: 10.1073/pnas.2011577118

Toxin-antitoxin regulates plasmid replication

Photo by Adrian Lange on Unsplash

Photo by Adrian Lange on Unsplash

What is it about?

In this work, we demonstrate the functional significance of a large group of antitoxins on conjugative plasmids: the antitoxin PrpA acts as an novel player in the negative control of plasmid replication, by binding to the iterons in the plasmid origin that inhibits the binding of the replication initiator to the iterons.

Why is it important?

This work shows that the antitoxin can directly regulate plasmid replication, expanding our understanding of the physiological role of TA systems.


Xiaoxue Wang
Chinese Academy of Sciences

Additional investigations are warranted to explore whether this TA pair regulates the replication of virulence plasmids during infection. It would also be important to explore whether plasmid-encoded antitoxins are engaged in the regulation of virulence and antibiotic resistance genes in addition to acting as the antidote for the toxin.

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The following have contributed to this page: Xiaoxue Wang, Pengxia Wang, and Songwei Ni