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Published on: September 1, 2018
Doc of prophage P1 is inhibited by its antitoxin partner Phd through fold complementation
Abel Garcia-Pino1, Mikkel Christensen-Dalsgaard, Lode Wyns
1Laboratorium voor Ultrastructuur, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussel, Belgium.
The Journal of Biological Chemistry
|September 2, 2008
Summary
The toxin Doc, from phage P1, inhibits bacterial growth by targeting protein synthesis. Its interaction with the antitoxin Phd reveals molecular details and suggests an evolutionary link to Fic proteins.
Area of Science:
- Molecular biology
- Bacteriology
- Genetics
Background:
- Prokaryotic toxin-antitoxin (TA) modules regulate physiological events during stress.
- The phd/doc module from phage P1 encodes the toxin Doc and antitoxin Phd.
- Phd binds the C-terminal domain of Doc via fold complementation.
Purpose of the Study:
- To elucidate the molecular interactions between Doc and Phd.
- To understand the mechanism of Doc-mediated growth arrest.
- To explore the evolutionary origins of the phd/doc operon.
Main Methods:
- Protein structure analysis
- In vivo growth assays in Escherichia coli
- Analysis of toxin-antitoxin interactions
Main Results:
- The Phd antitoxin domain is intrinsically disordered and folds upon binding to Doc.
- Doc induces reversible growth arrest in E. coli by inhibiting protein synthesis.
- Doc activates the endogenous RelE mRNA interferase but is independent of other TA loci.
Conclusions:
- The Doc-Phd interaction reveals the molecular basis of antitoxin inhibition.
- The Doc-Phd complex structure resembles Fic proteins, suggesting evolutionary links.
- Doc's mechanism of action involves targeting protein synthesis and activating RelE.
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