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Site-specific Bacterial Chromosome Engineering: ΦC31 Integrase Mediated Cassette Exchange (IMCE)
Published on: March 16, 2012
Highly efficient in vitro site-specific recombination system based on streptomyces phage phiBT1 integrase
Lin Zhang1, Xijun Ou, Guoping Zhao
1Department of Microbiology and Microbial Engineering, School of Life Sciences, Fudan University, Shanghai 200433, China.
Journal of Bacteriology
|August 12, 2008
Summary
The Streptomyces phage phiBT1 integrase efficiently mediates site-specific DNA recombination in vitro. This serine recombinase shows high specificity and rapid kinetics for integration and excision, with potential applications in DNA manipulation.
Area of Science:
- Molecular Biology
- Biochemistry
- Microbial Genetics
Background:
- The Streptomyces phage phiBT1 harbors a site-specific integrase belonging to the large serine recombinase family.
- Understanding the enzymatic activity of such integrases is crucial for their application in genetic engineering and DNA manipulation.
Purpose of the Study:
- To characterize the in vitro enzymatic activity of the phiBT1 integrase.
- To evaluate its efficiency, specificity, and kinetics in DNA recombination reactions.
Main Methods:
- In vitro characterization of phiBT1 integrase activity using substrate DNAs containing attB and attP sites.
- Assays to determine the kinetics of intra- and intermolecular recombination.
- Specificity testing with various att site combinations (attB, attP, attL, attR) and assessment of minimal att site sizes.
Main Results:
- The phiBT1 integrase exhibits efficient integration activity with attB and attP sites, independent of DNA supercoiling or cofactors.
- Both intramolecular and intermolecular recombination reactions proceed rapidly and with high specificity.
- A low but significant frequency of excision recombination between attL and attR was observed with the integrase alone; minimal attB and attP sizes were determined to be 36 bp and 48 bp, respectively.
Conclusions:
- The phiBT1 integrase is a highly efficient and specific site-specific recombination system.
- Its simplicity and efficiency suggest potential applications for in vitro DNA manipulation and genetic engineering.
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