Processive action of T4 endonuclease V on ultraviolet-irradiated DNA

R. Stephen Lloyd, Philip C. Hanawalt, Marion L. Dodson

Research output: Contribution to journalArticlepeer-review

36 Scopus citations


The action of the dimer-specific endonuclease V of bacteriophage T4 was studied on UV-irradiated, covalently-closed circular DNA. Form I ColEl DNA preparations containing average dimer frequencies ranging from 2.5 to 35 pyrimidine dimers per molecule were treated with T4 endonuclease V and analysed by agarose gel electrophoresis. At all dimer frequencies examined, the production of form III DNA was linear with time and the double-strand scissions were made randomly on the ColEl DNA genome. Since the observed fraction of form III DNA increased with increasing dimer frequency but the initial rate of loss of form I decreased with increasing dimer frequency, it was postulated that multiple single-strand scissions could be produced in a subset of the DNA population while some DNA molecules contained no scissions. When DNA containing an average of 25 dimers per circle was incubated with limiting enzyme concentrations, scissions appeared at most if not all dimer sites in some molecules before additional strand scissions were produced in other DNA molecules. The results support a processive model for the interaction of T4 endonuclease V with UV-irradiated DNA.

Original languageEnglish (US)
Pages (from-to)5113-5127
Number of pages15
JournalNucleic acids research
Issue number21
StatePublished - Nov 11 1980
Externally publishedYes

ASJC Scopus subject areas

  • Genetics


Dive into the research topics of 'Processive action of T4 endonuclease V on ultraviolet-irradiated DNA'. Together they form a unique fingerprint.

Cite this