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Updated: Aug 6, 2026
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Site-specific Bacterial Chromosome Engineering: ΦC31 Integrase Mediated Cassette Exchange (IMCE)
Published on: March 16, 2012
Isolation and analysis of a circular form of the IncJ conjugative transposon-like elements, R391 and R997:
1Molecular Biochemistry Group, University of Limerick, Limerick, Ireland. tony.pembroke@ul.ie
FEMS Microbiology Letters
|June 17, 2000
Summary
Incompatibility between IncJ elements R997 and R391 in Escherichia coli was studied. In a recA background, these elements can coexist as plasmids, revealing their ability for autonomous replication.
Area of Science:
- Microbiology
- Molecular Biology
- Genetics
Background:
- IncJ elements are conjugative transposon-like elements.
- These elements typically integrate into the host chromosome.
- Incompatibility usually prevents co-existence of multiple IncJ elements.
Purpose of the Study:
- To investigate the incompatibility mechanism of IncJ elements R997 and R391.
- To explore the conditions under which multiple IncJ elements can coexist.
- To characterize the molecular behavior of IncJ elements in different genetic backgrounds.
Main Methods:
- Construction of Escherichia coli strains harboring both R997 and R391 elements.
- Analysis of strains in both recA(+) and recA(-) backgrounds.
- Plasmid isolation and characterization.
- Restriction fragment analysis of isolated elements.
Main Results:
- recA(+) strains showed evidence of recombinant hybrids, not independent co-existence.
- recA(-) strains allowed stable co-existence of both IncJ elements as plasmids.
- Plasmids of 93.9 kb (R391 with integrated R997) and 85 kb (R997 with integrated R391) were isolated.
- Restriction patterns indicated a close physical relationship between R997 and R391.
Conclusions:
- IncJ elements possess latent autonomous replication ability.
- This ability is revealed in a recA background when the chromosomal integration site is occupied.
- The findings provide insights into IncJ incompatibility and a method for isolating these elements.
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