Related Experiment Videos
A novel plasmid gene involved in bacteriophage PRD1 infection and conjugative host-range
1Department of Biology, Carleton University, Ottawa, Ontario, Canada. mholcik@hhmivax.humgen.upenn.edu
Abstract:
PRD1 infects bacteria carrying IncN plasmids by binding to their conjugative pili. Mutations in a plasmid locus kikA close to the pilus region result in PRD1 resistance and reduced conjugation proficiency to Klebsiella but not to Escherichia coli. One of the two genes of kikA is sufficient to restore both normal phenotypes. PRD1 binds to cells carrying the mutant plasmid but fails to inject its genome.
Insights
Bacteriophage PRD1 resistance in bacteria with IncN plasmids is linked to mutations in the kikA locus. One kikA gene restores normal phage infection and bacterial conjugation, impacting host-phage interactions.
Area of Science:
- Microbiology
- Virology
- Genetics
Background:
- Bacteriophage PRD1 infects bacteria by attaching to conjugative pili, which are encoded by IncN plasmids.
- The IncN plasmid locus kikA is located near the pilus region and influences PRD1 infection and bacterial conjugation.
Purpose of the Study:
- To investigate the role of the kikA locus in PRD1 resistance and bacterial conjugation.
- To determine which gene within kikA is responsible for restoring normal phenotypes.
Main Methods:
- Analyzing mutations in the kikA locus of IncN plasmids.
- Assessing PRD1 resistance and conjugation proficiency in modified bacteria (Klebsiella and Escherichia coli).
- Evaluating the effect of individual kikA genes on bacterial phenotypes.
Main Results:
- Mutations in kikA confer PRD1 resistance and reduce conjugation in Klebsiella but not E. coli.
- One of the two kikA genes is sufficient to restore both PRD1 susceptibility and normal conjugation.
- PRD1 binds to cells with mutant plasmids but cannot inject its genome, indicating a block in infection.
Conclusions:
- The kikA locus plays a crucial role in mediating PRD1 infection and bacterial conjugation.
- Specific genes within kikA are essential for host-bacteriophage interactions and plasmid transfer.
- Understanding kikA function provides insights into phage resistance mechanisms and bacterial genetics.