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Identification of the Chlamydia trachomatis RecA-encoding gene
1Department of Medical Microbiology, University of Manitoba, Winnipeg, Canada.
Infection and Immunity
|February 1, 1995
Summary
Researchers identified a RecA homolog in Chlamydia trachomatis, suggesting homologous recombination may occur in this bacterium. This finding aids in developing genetic tools for Chlamydia trachomatis research.
Area of Science:
- Microbiology
- Molecular Biology
- Genetics
Background:
- Chlamydia trachomatis major outer membrane protein (MOMP) gene sequencing revealed mosaic structures.
- These structures suggest homologous recombination between distinct omp1 genes.
Purpose of the Study:
- To clone and sequence the RecA homolog from Chlamydia trachomatis serovar L2.
- To investigate the potential for homologous recombination in Chlamydia.
Main Methods:
- Cloning by complementation in RecA-deficient Escherichia coli.
- Selection for methyl methanesulfonate (MMS) resistance and isolation of lac+ recombinants.
- Immunoblot assay using anti-RecA antibodies and DNA sequencing.
Main Results:
- A 2.1-kb fragment (pX203) conferred MMS resistance to E. coli.
- Immunoblotting confirmed a 35-kDa antigen reactive with anti-RecA antibodies.
- Sequencing identified a 1,056 bp open reading frame encoding 352 amino acids with 44% identity to E. coli RecA.
Conclusions:
- The identified RecA homolog suggests homologous recombination occurs in Chlamydia trachomatis.
- The cloned gene is valuable for future construction of Chlamydia recA mutants.