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A novel DNA polymerase induced by Bacillus subtilis phage phi 29
Nucleic Acids Research
|December 10, 1983
Summary
Researchers identified a new DNA polymerase in Bacillus subtilis bacteriophage phi 29. This enzyme, encoded by gene 2, is crucial for initiating viral DNA replication by forming a protein-DNA complex.
Area of Science:
- Molecular Biology
- Virology
- Biochemistry
Background:
- Bacillus subtilis bacteriophage phi 29 is a well-studied model organism for DNA replication.
- Bacterial viruses encode their own DNA polymerases, distinct from host enzymes.
Purpose of the Study:
- To identify and characterize the DNA polymerase induced by bacteriophage phi 29.
- To determine the role of gene 2 in bacteriophage phi 29 DNA replication.
Main Methods:
- Fractionation of cell extracts using phosphocellulose chromatography.
- Enzyme activity assays using specific DNA templates.
- Analysis of temperature-sensitive mutants to assess enzyme function.
Main Results:
- A novel DNA polymerase was isolated from phi 29 infected cells, separable from host DNA polymerase.
- The isolated polymerase showed preference for a poly(dA)oligo(dT) template.
- A temperature-sensitive mutant (ts2) in gene 2 produced a thermolabile DNA polymerase.
- The ts2 DNA polymerase exhibited heat lability in forming the initiation complex for phi 29 DNA replication.
Conclusions:
- Gene 2 encodes the Bacillus subtilis bacteriophage phi 29 DNA polymerase.
- This polymerase is essential for the initiation step of phi 29 DNA replication, specifically for covalent complex formation.