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Preparation of the Mgm101 Recombination Protein by MBP-based Tagging Strategy
Published on: June 25, 2013
The lambda red proteins promote efficient recombination between diverged sequences: implications for bacteriophage
Jann T Martinsohn1, Miroslav Radman, Marie-Agnès Petit
1Faculté de Médecine R. Descartes, INSERM U571, Université Paris Descartes, Paris, France.
Plos Genetics
|May 3, 2008
Summary
Bacterial viruses (bacteriophages) exhibit extensive genome mosaicism due to efficient homeologous recombination. The virus
Area of Science:
- Molecular Biology
- Virology
- Genetics
Background:
- Genome mosaicism in temperate bacterial viruses (bacteriophages) is extensive, obscuring their phylogeny.
- The precise molecular mechanisms driving this viral genome mosaicism remain largely unknown.
- Both illegitimate recombination and homeologous recombination have been proposed as potential causes.
Purpose of the Study:
- To investigate the role of homeologous recombination in bacteriophage genome mosaicism.
- To compare the efficiency of viral and host recombination pathways in mediating homeologous recombination.
Main Methods:
- Quantified homeologous recombination efficiency between diverged oxa gene pairs inserted into lambda phage.
- Assessed the impact of the bacteriophage lambda Red Gam pathway versus the host Escherichia coli RecABCD pathway.
- Evaluated the effects of recombination editing proteins MutS and UvrD on lambda recombination.
Main Results:
- High yields of recombinants were achieved between 22% diverged genes with the active lambda Red Gam pathway.
- The host Escherichia coli RecABCD pathway yielded 100-fold fewer recombinants compared to the viral pathway.
- Recombination editing proteins MutS and UvrD had minimal impact on lambda recombination, suggesting host editing escape is crucial.
Conclusions:
- The bacteriophage lambda Red and Gam proteins exhibit a high propensity to recombine diverged DNA, contributing significantly to viral genome mosaicism.
- Escape from host DNA repair and editing mechanisms enhances the efficiency of viral recombination.
- A potential correlation exists between the degree of viral genome mosaicism and the presence of Red/Gam-like systems in viruses.
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