Discovery of Functional Toxin/Antitoxin Systems in Bacteria by Shotgun Cloning
Toxin-antitoxin (TA) modules, composed of a toxic protein and a counteracting antitoxin, play important roles in bacterial physiology. We examined the experimental insertion of 1.5 million genes from 388 microbial genomes into an Escherichia coli host using over 8.5 million random clones. This revealed hundreds of genes (toxins) that could only be cloned when the neighboring gene (antitoxin) was present on the same clone. Clustering of these genes revealed TA families widespread in bacterial genomes, some of which deviate from the classical characteristics previously described for such modules. Introduction of these genes into E. coli validated that the toxin toxicity is mitigated by the antitoxin. Infection experiments with T7 phage showed that two of the new modules can provide resistance against phage. Moreover, our experiments revealed an 'anti-defense' protein in phage T7 that neutralizes phage resistance. Our results expose active fronts in the arms race between bacteria and phage.
- Research Organization:
- Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, CA (US)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- AC02-05CH11231
- OSTI ID:
- 1241209
- Report Number(s):
- LBNL-7068E
- Journal Information:
- Molecular Cell, Journal Name: Molecular Cell Journal Issue: 1 Vol. 50; ISSN 1097-2765
- Publisher:
- Elsevier - Cell Press
- Country of Publication:
- United States
- Language:
- English
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