Recombinant Bacillus phage phi29 DNA polymerase (2)

Function

Polymerase responsible for protein-primed viral DNA replication by strand displacement with high processivity and fidelity (PubMed:2498321, PubMed:3863101). To start replication, the DNA polymerase forms a heterodimer with a free primer terminal protein (TP), recognizes the replication origins at both 5' ends of the linear chromosome, and initiates replication using as primer the OH-group of Ser-232 of the TP (PubMed:22210885). This polymerase possesses three enzymatic activities: DNA synthesis (polymerase), primer terminal protein (TP) deoxynucleotidylation, which is the formation of a covalent linkage (phosphoester) between the hydroxyl group of a specific serine residue in TP and 5'-dAMP, a reaction directed by the second T at the 3' end, and 3' to 5' exonuclease activity (PubMed:2790959). Exonuclease activity has a proofreading purpose (PubMed:2790959). DNA polymerase edits the polymerization errors using an intramolecular pathway as the primer terminus travels from one active site to the other without dissociation from the DNA (PubMed:10493855). DNA polymerization catalyzed by the DNA polymerase is a highly accurate process, but the protein-primed initiation is a quite inaccurate reaction (PubMed:8428945). Since the polymerase initiates the replication on the second thymine, the TP-dAMP initiation product translocates backwards to recover the template information of the first nucleotide (sliding back-mechanism) (PubMed:19011105)

Subunit

Interacts with the primer terminal protein; this interaction allows the initiation of TP-primed DNA replication at both viral DNA ends. Interacts with DNA

• Yoshikawa H. et al. Nucleotide sequence of the major early region of bacteriophage phi 29. — Gene (1982)
• Villegas A.P. et al. PubMed: CI-FVG32IOQ8HNFG (MAY-)
• Escarmis C. et al. Nucleotide sequence of the early genes 3 and 4 of bacteriophage phi 29. — Nucleic Acids Res. (1982)
• Blasco M.A. et al. Structural and functional analysis of temperature-sensitive mutants of the phage phi 29 DNA polymerase. — Nucleic Acids Res. (1990)
• Blanco L. et al. Replication of phage phi 29 DNA with purified terminal protein and DNA polymerase: synthesis of full-length phi 29 DNA. — Proc. Natl. Acad. Sci. U.S.A. (1985)
• Blanco L. et al. Highly efficient DNA synthesis by the phage phi 29 DNA polymerase. Symmetrical mode of DNA replication. — J. Biol. Chem. (1989)
• Bernad A. et al. A conserved 3'->5' exonuclease active site in prokaryotic and eukaryotic DNA polymerases. — Cell (1989)
• Bernad A. et al. The highly conserved amino acid sequence motif Tyr-Gly-Asp-Thr-Asp-Ser in alpha-like DNA polymerases is required by phage phi 29 DNA polymerase for protein-primed initiation and polymerization. — Proc. Natl. Acad. Sci. U.S.A. (1990)