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Updated: Aug 3, 2026
06:10
Following Cell-fate in E. coli After Infection by Phage Lambda
Published on: October 14, 2011
rexB of bacteriophage lambda is an anti-cell death gene
H Engelberg-Kulka1, M Reches, S Narasimhan
1Department of Molecular Biology, Hebrew University-Hadassah Medical School, Jerusalem 91120 Israel. hanita@cc.huji.ac.il
Summary
Lambda bacteriophage RexB protein prevents cell death in Escherichia coli by inhibiting the degradation of key cellular components. This survival function, mediated by the rex operon, protects lysogenic cells during nutrient starvation.
Area of Science:
- Molecular Biology
- Microbiology
- Genetics
Background:
- Programmed cell death in Escherichia coli is regulated by addiction modules.
- These modules involve a stable toxic component and a labile antitoxin.
- Bacteriophage lambda's lysogenic state involves the expression of the rex operon.
Purpose of the Study:
- To investigate the role of lambda RexB in preventing cell death.
- To determine if lambda RexB counteracts known addiction modules in E. coli.
- To elucidate the mechanism of lambda RexB's anti-cell death activity.
Main Methods:
- Investigated the interaction of lambda RexB with E. coli addiction modules (phd-doc and rel mazEF).
- Assessed the effect of lambda RexB on the stability of antitoxins Phd and MazE.
- Proposed a model for lambda RexB's mechanism of action on ClpP proteases.
Main Results:
- Lambda RexB prevents cell death induced by the phd-doc and rel mazEF addiction modules.
- Lambda RexB inhibits the ClpP-mediated degradation of antitoxins Phd and MazE.
- The rex operon may function as a survival operon for phage lambda.
Conclusions:
- Lambda RexB possesses an anti-cell death function, protecting lysogenic cells from starvation-induced death.
- The rex operon's role extends beyond phage exclusion to include cell survival.
- This suggests a novel survival strategy for bacteriophage lambda.
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