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Updated: Feb 23, 2026
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Following Cell-fate in E. coli After Infection by Phage Lambda
Published on: October 14, 2011
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Domestication of Lambda Phage Genes into a Putative Third Type of Replicative Helicase Matchmaker
Pierre Brézellec1, Marie-Agnès Petit2, Sophie Pasek3
1Universite de Versailles Saint-Quentin en Yvelines UFR des Sciences, France.
Genome Biology and Evolution
|September 1, 2017
Summary
Researchers discovered novel phage-derived genes, dopC and dopE, that substitute for essential DciA proteins in some bacteria. This finding suggests a conserved mechanism for loading replicative helicases across all life.
Area of Science:
- Microbiology
- Molecular Biology
- Genetics
Background:
- Bacterial DNA replication initiation requires loading of replicative helicases onto the DnaA-oriC platform.
- Proteins like DnaC/DnaI and DciA typically assist this process.
- Some bacterial lineages lack these known accessory factors, posing questions about replication initiation mechanisms.
Purpose of the Study:
- To investigate the mechanisms of replicative helicase loading in bacteria lacking DnaC/DnaI and DciA.
- To identify potential alternative factors involved in initiating DNA replication in these organisms.
Main Methods:
- Phylogenomic analysis was employed to identify candidate genes.
- Investigated the evolutionary origin of these candidate genes from lambdoid phages.
Main Results:
- Identified a pair of domesticated lambdoid phage genes, dopC and dopE, specific to bacteria lacking dciA and dnaC/dnaI.
- DopE is hypothesized to deliver the replicative helicase to the origin, with DopC potentially assisting.
- These genes appear to have originated from bacteriophage lambda (λ) O and P genes.
Conclusions:
- The dopC and dopE genes represent a functional substitution for dciA in certain bacteria.
- The discovery of DopCE suggests a conserved requirement for accessory factors in replicative helicase loading across bacteria.
- This finding could generalize to all living organisms, highlighting fundamental mechanisms of DNA replication initiation.
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