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Site-specific Bacterial Chromosome Engineering: ΦC31 Integrase Mediated Cassette Exchange (IMCE)
Published on: March 16, 2012
Efficiency of recombination reactions catalyzed by class 1 integron integrase IntI1
C M Collis1, G D Recchia, M J Kim
1CSIRO Molecular Science, Sydney Laboratory, North Ryde, New South Wales 1670, Australia.
Journal of Bacteriology
|March 29, 2001
Summary
Class 1 integron integrase (IntI1) mediates recombination between attI sites and 59-be sites. IntI1 prefers attI x 59-be recombination over 59-be x 59-be, with attI x attI being least efficient.
Area of Science:
- Molecular Biology
- Genetics
- Microbiology
Background:
- Integrons are genetic elements that facilitate gene acquisition.
- Class 1 integrons utilize the integrase IntI1 for site-specific recombination.
- Gene cassettes are mobile DNA elements carrying antibiotic resistance genes.
Purpose of the Study:
- To compare the efficiencies of different recombination reactions mediated by IntI1.
- To elucidate the substrate preferences of IntI1 for attI and 59-be sites.
- To understand the mechanism of integron assembly and gene cassette integration.
Main Methods:
- In vitro recombination assays were performed.
- Quantification of recombination products was achieved using gel electrophoresis and densitometry.
- Comparison of reaction efficiencies between attI x attI, attI x 59-be, and 59-be x 59-be substrates.
Main Results:
- Recombination between two attI sites (attI x attI) was significantly less efficient than reactions involving 59-be sites.
- The attI x 59-be reaction was generally preferred over the 59-be x 59-be reaction.
- IntI1 showed higher efficiency in recombining attI sites with secondary sites compared to 59-be sites with secondary sites.
Conclusions:
- IntI1 exhibits distinct substrate preferences for recombination.
- The attI x 59-be interaction is favored, suggesting a specific role in integron formation.
- Understanding these preferences is crucial for comprehending gene cassette dynamics and integron evolution.
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