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Identification of a protein bound to the termini of bacteriophage PRD1 DNA
Abstract:
Lipid-containing bacteriophage PRD1 has a double-stranded DNA genome of about 14,500 nucleotide base pairs. The phage can infect Escherichia coli and Salmonella typhimurium as well as other gram-negative bacteria harboring an appropriate plasmid. [35S]methionine label is incorporated into the DNA band early in infection. The label remains associated with DNA through phenol extraction and boiling with sodium dodecyl sulfate. Nuclease treatment of the genome released a protein which migrated as an early phage-specific protein (P8). This protein is also necessary for phage DNA replication. By restriction enzyme analysis it was shown that protein was associated with the terminal restriction fragments. Extracts of infected cells catalyzed the labeling of protein P8 with [alpha-32P]dGTP.
Insights
Bacteriophage PRD1, a virus infecting bacteria like E. coli, has a protein (P8) essential for its DNA replication. This protein is found at the ends of the viral DNA, indicating its crucial role in the infection process.
Area of Science:
- Virology
- Molecular Biology
- Bacteriophage Research
Background:
- Bacteriophage PRD1 is a lipid-containing virus with a double-stranded DNA genome.
- It infects gram-negative bacteria such as Escherichia coli and Salmonella typhimurium.
Purpose of the Study:
- To investigate the role of early phage-specific proteins in bacteriophage PRD1 infection.
- To identify the function and location of protein P8 during phage DNA replication.
Main Methods:
- Incorporation of [35S]methionine label into phage DNA.
- Nuclease digestion of the phage genome to release associated proteins.
- Restriction enzyme analysis to determine protein association with DNA fragments.
- In vitro labeling of protein P8 with [alpha-32P]dGTP.
Main Results:
- Protein P8, an early phage-specific protein, was released from the PRD1 genome by nuclease treatment.
- Protein P8 is essential for bacteriophage PRD1 DNA replication.
- Restriction enzyme analysis revealed protein P8 is associated with the terminal DNA fragments.
- Extracts from infected cells could label protein P8.
Conclusions:
- Protein P8 plays a critical role in bacteriophage PRD1 DNA replication.
- The association of protein P8 with terminal DNA fragments suggests a role in DNA packaging or initiation of replication.