Light-induced activation of class II cyclobutane pyrimidine dimer photolyases

Asako Okafuji, Till Biskup, Kenichi Hitomi, Elizabeth D. Getzoff, Gebhard Kaiser, Alfred Batschauer, Adelbert Bacher, Jun Hidema, Mika Teranishi, Kazuo Yamamoto, Erik Schleicher, Stefan Weber

    Research output: Contribution to journalArticlepeer-review

    26 Citations (Scopus)


    Light-induced activation of class II cyclobutane pyrimidine dimer (CPD) photolyases of Arabidopsis thaliana and Oryza sativa has been examined by UV/Vis and pulsed Davies-type electron-nuclear double resonance (ENDOR) spectroscopy, and the results compared with structure-known class I enzymes, CPD photolyase and (6-4) photolyase. By ENDOR spectroscopy, the local environment of the flavin adenine dinucleotide (FAD) cofactor is probed by virtue of proton hyperfine couplings that report on the electron-spin density at the positions of magnetic nuclei. Despite the amino-acid sequence dissimilarity as compared to class I enzymes, the results indicate similar binding motifs for FAD in the class II photolyases. Furthermore, the photoreduction kinetics starting from the FAD cofactor in the fully oxidized redox state, FADox, have been probed by UV/Vis spectroscopy. In Escherichia coli (class I) CPD photolyase, light-induced generation of FADH{radical dot} from FADox, and subsequently FADH- from FADH{radical dot}, proceeds in a step-wise fashion via a chain of tryptophan residues. These tryptophans are well conserved among the sequences and within all known structures of class I photolyases, but completely lacking from the equivalent positions of class II photolyase sequences. Nevertheless, class II photolyases show photoreduction kinetics similar to those of the class I enzymes. We propose that a different, but also effective, electron-transfer cascade is conserved among the class II photolyases. The existence of such electron transfer pathways is supported by the observation that the catalytically active fully reduced flavin state obtained by photoreduction is maintained even under oxidative conditions in all three classes of enzymes studied in this contribution.

    Original languageEnglish
    Pages (from-to)495-505
    Number of pages11
    JournalDNA Repair
    Issue number5
    Publication statusPublished - 2010 May 4


    • DNA repair
    • Electron-nuclear double resonance
    • Electron-paramagnetic resonance
    • Flavoprotein
    • Photolyase
    • UV/blue light

    ASJC Scopus subject areas

    • Biochemistry
    • Molecular Biology
    • Cell Biology


    Dive into the research topics of 'Light-induced activation of class II cyclobutane pyrimidine dimer photolyases'. Together they form a unique fingerprint.

    Cite this