Protein-primed replication of bacteriophage phi 29 DNA

Biochim Biophys Acta. 1988 Dec 20;951(2-3):419-24. doi: 10.1016/0167-4781(88)90115-7.


The replication of phi 29 DNA-protein p3 represents a simple model system to study the protein-priming mechanism of initiation of replication. The phi 29 DNA polymerase involved both in the initiation and elongation steps of phi 29 DNA-protein p3 replication, is a very processive enzyme and it is able to produce strand-displacement in the absence of other proteins. To correlate functional and structural domains in the phi 29 DNA polymerase point mutants in the most carboxyl region of amino-acid homology with other DNA polymerases have been constructed. Most of the mutations had a decreased initiation and elongation activity, but normal 3'----5' exonuclease activity, suggesting that this region contributes to the active domain for initiation and elongation. Point and deletion mutants in the terminal protein have allowed the mapping of one DNA-binding region and two DNA-polymerase-binding regions. The viral protein p6, which stimulates the initiation of replication, binds to a set of specific signals present at both phi 29 DNA ends. A good correlation of binding and stimulation of replication has been obtained by using fragments containing phi 29 DNA-terminal sequences and deletion mutants of protein p6. The viral protein p5 has been shown to bind to single-stranded DNA, to protect the latter against nuclease digetion, and to stimulate phi 29 DNA-protein p3 replication in vitro.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Bacteriophages / genetics*
  • Bacteriophages / physiology
  • Catalysis
  • DNA Replication*
  • DNA, Viral / metabolism
  • DNA-Directed DNA Polymerase / genetics
  • DNA-Directed DNA Polymerase / metabolism
  • Exodeoxyribonuclease V
  • Exodeoxyribonucleases / metabolism
  • Mutation
  • Sequence Homology, Nucleic Acid
  • Viral Proteins / metabolism
  • Viral Proteins / pharmacology*
  • Virus Replication*


  • DNA, Viral
  • Viral Proteins
  • DNA-Directed DNA Polymerase
  • Exodeoxyribonucleases
  • Exodeoxyribonuclease V