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Characterization of the lysogenic bacteriophage MAV1 from Mycoplasma arthritidis
1Department of Comparative Medicine, University of Alabama at Birmingham, Birmingham, Alabama 35294-0019, USA.
Abstract:
The lysogenic bacteriophage MAV1, which is associated with the arthritogenicity of Mycoplasma arthritidis, was characterized. Several strains of M. arthritidis were examined for their ability to support growth of MAV1. A PFU assay was developed, and the sensitivity of phage to various chemical treatments was assayed. The most notable result was the resistance of MAV1 to proteinase K. The MAV1 genome is a double-stranded, linear DNA molecule of about 16 kb. The site of MAV1 DNA integration in the host chromosome was investigated. The ends of MAV1 DNA were cloned from three independent lysogens shown to have MAV1 DNA inserted at different sites in the host. The nucleotide sequences of the ends of the MAV1 genome and of the MAV1 DNA-chromosomal DNA junctions from each of three lysogens were determined. Sequences flanking the integrated prophage and the ends of native MAV1 DNA were determined, allowing the identification of the phage DNA (attP) and bacterial DNA (attB) recombination sites. Analysis of the left MAV1 DNA-chromosomal DNA junction sites showed a single-base heterogeneity located within MAV1 DNA sequences immediately adjacent to the attB sequence. A model for MAV1 integration-excision is proposed.
Insights
The lysogenic bacteriophage MAV1, linked to Mycoplasma arthritidis, was characterized. Its DNA integration sites and resistance to proteinase K were detailed, proposing a model for its lifecycle.
Area of Science:
- Microbiology
- Virology
- Molecular Biology
Background:
- Mycoplasma arthritidis is associated with arthritis.
- Lysogenic bacteriophages can influence host pathogenicity.
- The bacteriophage MAV1 is linked to M. arthritidis arthritogenicity.
Purpose of the Study:
- To characterize the lysogenic bacteriophage MAV1.
- To investigate the integration mechanism of MAV1 DNA into the host genome.
- To understand the role of MAV1 in M. arthritidis-associated arthritis.
Main Methods:
- Phage plaque-forming unit (PFU) assay for MAV1 growth.
- Sensitivity assays for MAV1 against chemical treatments.
- Cloning and sequencing of MAV1 DNA ends and host integration junctions.
- Identification of phage (attP) and bacterial (attB) recombination sites.
Main Results:
- MAV1 demonstrated resistance to proteinase K.
- MAV1 possesses a double-stranded, linear DNA genome (~16 kb).
- Integration sites of MAV1 DNA into the host chromosome were identified at multiple locations.
- A single-base heterogeneity was observed near the attB site in MAV1 DNA.
Conclusions:
- MAV1 integration into the M. arthritidis chromosome is site-specific but can occur at different locations.
- A model for MAV1 integration and excision has been proposed based on sequence analysis.
- Further research is needed to fully elucidate MAV1's role in arthritogenicity.