Chlorella virus pyrimidine dimer glycosylase excises ultraviolet radiation- and hydroxyl radical-induced products 4,6-diamino-5-formamidopyrimidine and 2,6-diamino-4-hydroxy-5-formamidopyrimidine from DNA

Pawel Jaruga, Ritche Jabil, Amanda K. McCullough, Henry Rodriguez, Miral Dizdaroglu, R. Stephen Lloyd

Research output: Contribution to journalArticle

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Abstract

A DNA glycosylase specific for UV radiation-induced pyrimidine dimers has been identified from the Chlorella virus Paramecium Bursaria Chlorella virus-1. This enzyme (Chlorella virus pyrimidine dimer glycosylase [cvpdg]) exhibits a 41% amino acid identity with endonuclease V from bacteriophage T4 (T4 pyrimidine dimer glycosylase [T4-pdg]), which is also specific for pyrimidine dimers. However, cv-pdg possesses a higher catalytic efficiency and broader substrate specificity than T4-pdg. The latter excises 4,6-diamino-5-formamidopyrimidine (FapyAde), a UV radiation- and hydroxyl radical-induced monomeric product of adenine in DNA. Using gas chromatography-isotope-dilution mass spectrometry and γ-irradiated DNA, we show in this work that cv-pdg also displays a catalytic activity for excision of FapyAde and, in addition, it excises 2,6-diamino-4-hydroxy-5-formamidopyrimidine (FapyGua). Kinetic data show that FapyAde is a better substrate for cv-pdg than FapyGua. On the other hand, cv-pdg possesses a greater efficiency for the extension of FapyAde than T4-pdg. These two enzymes exhibit different substrate specificities despite substantial structural similarities.

Original languageEnglish (US)
Pages (from-to)85-91
Number of pages7
JournalPhotochemistry and photobiology
Volume75
Issue number2
DOIs
StatePublished - Feb 1 2002

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ASJC Scopus subject areas

  • Biochemistry
  • Physical and Theoretical Chemistry

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