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Site-specific Bacterial Chromosome Engineering: ΦC31 Integrase Mediated Cassette Exchange (IMCE)
Published on: March 16, 2012
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Compatibility of Site-Specific Recombination Units between Mobile Genetic Elements.
Shota Suzuki1, Miki Yoshikawa2, Daisuke Imamura2
1Research Center of Micro-Nano Technology, Hosei University, Koganei, Tokyo 184-0003, Japan.
Iscience
|January 12, 2020
Summary
Site-specific recombination (SSR) units from different mobile genetic elements (MGEs) are interchangeable. Introducing SSR units from skin or ICEBs1 can restore activity to a defective SPβ prophage in Bacillus subtilis.
Area of Science:
- Molecular Biology
- Microbial Genetics
- Bacteriophage Biology
Background:
- Site-specific recombination (SSR) systems mediate the integration and excision of mobile genetic elements (MGEs), including prophages and integrative conjugative elements (ICEs).
- These SSR systems involve specific DNA sites (attP/I and attB) and proteins like integrase (Int) and recombination directionality factor (RDF).
- Bacillus subtilis 168 harbors multiple MGEs, such as the SPβ prophage, skin prophage, and ICEBs1, each possessing a canonical SSR unit (attL-int-rdf-attR).
Purpose of the Study:
- To investigate the compatibility and interchangeability of SSR units from different MGEs in Bacillus subtilis.
- To determine if SSR units from one MGE can functionally replace those of another.
- To explore the role of SSR units in regulating gene rearrangements, such as those affecting kamA.
Main Methods:
- Genetic manipulation of Bacillus subtilis 168 to create a defective SPβ prophage by deleting its native SSR unit.
- Introduction of SSR units derived from the skin prophage and ICEBs1 into the modified SPβ.
- Analysis of prophage activity and gene rearrangement (kamA) following the introduction of heterologous SSR units.
Main Results:
- Demonstrated that the SSR units from SPβ, skin, and ICEBs1 are functionally compatible and can substitute for each other.
- Showed that introducing the SSR unit of skin or ICEBs1 can restore activity to a defective SPβ prophage.
- Identified related prophages with distinct SSR units that govern developmentally regulated rearrangements of the kamA gene.
Conclusions:
- SSR units are interchangeable components within MGEs, highlighting a modular nature of these genetic elements.
- The functional interchangeability of SSR units has implications for understanding MGE dynamics and evolution.
- SSR systems provide a mechanism for controlling gene rearrangements, impacting bacterial development and adaptation.
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