A DNA-protein complex was isolated from Bacillus subtilis bacteriophage phi29 by sucrose gradient sedimentation or gel filtration in the presence of agents known to break noncovalent bonds. A 28,000-dalton protein was released from this complex by subsequent hydrolysis of the DNA. The DNA-protein complex was examined for its susceptibility to enzymes which act upon the 5' and 3' termini of DNA molecules. It was susceptible to exonucleolytic degradation from the 3' termini by exonuclease III but not from the 5' termini by lambda exonuclease. Attempts to label radioactively the 5' termini by phosphorylation with T4 polynucleotide kinase were unsuccessful despite prior treatment with alkaline phosphatase or phosphatase treatment of denatured DNA. Removal of the majority of the bound protein by proteolytic digestion did not increase susceptibility. These results suggest that the linked protein is covalently attached to the 5' termini of phi29 DNA.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC525865 | PMC |
| http://dx.doi.org/10.1128/JVI.27.3.776-783.1978 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Inhibition of Endothelial Cell Tube Formation by Anti-Vascular Endothelial Growth Factor/Anti-Angiopoietin-2 RNA Nanoparticles.
Pharmaceutics
January 2025
Division of Pharmaceutical Sciences, James L Winkle College of Pharmacy, University of Cincinnati, Cincinnati, OH 45267, USA.
RNA nanoparticles, derived from the packaging RNA three-way junction motif (pRNA-3WJ) of the bacteriophage phi29 DNA packaging motor, have been demonstrated to be thermodynamically and chemically stable, with promise as a nanodelivery system. : A previous study showed that RNA nanoparticles with antiangiogenic aptamers (anti-vascular endothelial growth factor (VEGF) and anti-angiopoietin-2 (Ang2) aptamers) inhibited cell proliferation via WST-1 assay. To further investigate the antiangiogenic potential of these RNA nanoparticles, a modified three-dimensional (3D) spheroid sprouting assay model of human umbilical vein endothelial cells was utilized in the present study.
View Article and Find Full Text PDF[Mining and characterization of new enzymes based on Phi29 DNA polymerase].
Sheng Wu Gong Cheng Xue Bao
January 2025
Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China.
In recent years, the bacteriophage Φ29 (Phi29) DNA polymerase has garnered increasing attention due to its high-fidelity amplification capacity at constant temperatures. To advance the industrial application of this type of isothermal polymerases, this study mined and characterized new enzymes from the microbial metagenome based on the known Phi29 DNA polymerase sequence. The results revealed that a new enzyme, Php29 DNA polymerase, was identified in the microbial metagenome with plants as the hosts.
View Article and Find Full Text PDFComplete annotated genome sequence of phage Evcara, a cluster GI podovirus isolated from compost.
MicroPubl Biol
December 2024
Department of Chemistry and Physics, Western Carolina University, Cullowhee, North Carolina, US.
Bacteriophage Evcara is a podovirus isolated on NRRL B-24275. Its genome is 16,285 bp in length and contains 22 predicted protein-coding genes. Evcara, has been assigned to cluster GI with phages PineapplePizza and Curie that share 10 homologues with the well-characterized phage phi29.
View Article and Find Full Text PDFMethods for Studying Motor-Driven Viral DNA Packaging in Bacteriophages phi29, Lambda, and T4 via Single DNA Molecule Manipulation and Rapid Solution Exchange.
Methods Mol Biol
December 2024
Department of Physics, University of California San Diego, La Jolla, CA, USA.
Viral DNA packaging is a required step in the assembly of many dsDNA viruses. A molecular motor fueled by ATP hydrolysis packages the viral genome to near crystalline density inside a pre-formed prohead shell in ~5 min at room temperature in vitro. We describe procedures for measuring the packaging of single DNA molecules into single viral proheads with optical tweezers.
View Article and Find Full Text PDFDarwinian Evolution of Self-Replicating DNA in a Synthetic Protocell.
Nat Commun
October 2024
Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, Netherlands.
Replication, heredity, and evolution are characteristic of Life. We and others have postulated that the reconstruction of a synthetic living system in the laboratory will be contingent on the development of a genetic self-replicator capable of undergoing Darwinian evolution. Although DNA-based life dominates, the in vitro reconstitution of an evolving DNA self-replicator has remained challenging.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!