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Isolation and characterization of a new bacteriophage, KF1, immunologically cross-reactive with F-type pyocins
Abstract:
Pseudomonas aeruginosa strain NIH S produced a bacteriophage, KF1, immunologically cross-reactive with F-type pyocins. Phage KF1 was neutralized by both anti-pyocin F1 and anti-pyocin F3 sera, although the efficiency was very low. About eleven polypeptides were detected by SDS-polyacrylamide gel electrophoresis of the phage. Most of the subunit proteins were different from those of F-type pyocins, but the molecular weights of minor subunit proteins P3 and P6 seemed to be the same as those of band 1 and band 5 of F-type pyocins, respectively. The head of the phage appeared to have an icosahedral structure, approximately 63 nm in diameter, with a long (190 nm, 11 nm wide and about 45 striations) flexuous tail connected to a fiber structure (about 53 nm in length). The density in CsCl and the sedimentation coefficient of the phage were 1.54 g/ml and 392S, respectively. Some other biochemical properties were described. The nucleic acid of the phage was linear, double stranded DNA of molecular weight 4 x 10(7). The density of the DNA in CsCl was 1.719 g/ml, the melting temperature was 95.4 degrees C. The guanine plus cytosine content was calculated to be 60 to 64%.
Insights
Pseudomonas aeruginosa bacteriophage KF1 shows cross-reactivity with F-type pyocins. Structural and biochemical analysis revealed KF1
Area of Science:
- Microbiology
- Virology
- Molecular Biology
Background:
- Pseudomonas aeruginosa produces bacteriophages and pyocins.
- F-type pyocins are proteinaceous toxins with specific activity.
- Bacteriophage KF1 was isolated from P. aeruginosa strain NIH S.
Purpose of the Study:
- To characterize bacteriophage KF1.
- To investigate immunological cross-reactivity between KF1 and F-type pyocins.
- To determine the structural and biochemical properties of KF1.
Main Methods:
- SDS-polyacrylamide gel electrophoresis for polypeptide analysis.
- Electron microscopy for structural determination.
- CsCl density gradient centrifugation and sedimentation analysis.
- DNA extraction and characterization (density, melting temperature, GC content).
Main Results:
- KF1 showed low immunological cross-reactivity with F-type pyocins.
- Eleven polypeptides were detected in KF1, with some similarities to F-pyocin subunits.
- KF1 possesses an icosahedral head (63 nm) and a long, flexuous tail (190 nm).
- KF1 contains linear, double-stranded DNA (4 x 10^7 Da) with 60-64% GC content.
Conclusions:
- Bacteriophage KF1 shares some characteristics with F-type pyocins but is distinct.
- Structural and biochemical data provide a comprehensive profile of KF1.
- Further studies may elucidate the evolutionary relationship between KF1 and F-pyocins.