Recognition and repair of UV lesions in loop structures of duplex DNA by DASH-type cryptochrome

Proc Natl Acad Sci U S A. 2008 Dec 30;105(52):21023-7. doi: 10.1073/pnas.0805830106. Epub 2008 Dec 12.


DNA photolyases and cryptochromes (cry) form a family of flavoproteins that use light energy in the blue/UV-A region for the repair of UV-induced DNA lesions or for signaling, respectively. Very recently, it was shown that members of the DASH cryptochrome subclade repair specifically cyclobutane pyrimidine dimers (CPDs) in UV-damaged single-stranded DNA. Here, we report the crystal structure of Arabidopsis cryptochrome 3 with an in-situ-repaired CPD substrate in single-stranded DNA. The structure shows a binding mode similar to that of conventional DNA photolyases. Furthermore, CPD lesions in double-stranded DNA are bound and repaired with similar efficiency as in single-stranded DNA if the CPD lesion is present in a loop structure. Together, these data reveal that DASH cryptochromes catalyze light-driven DNA repair like conventional photolyases but lack an efficient flipping mechanism for interaction with CPD lesions within duplex DNA.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / enzymology*
  • Arabidopsis / genetics
  • Arabidopsis Proteins / chemistry*
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism
  • Cryptochromes
  • Crystallography, X-Ray
  • DNA Damage / physiology
  • DNA Damage / radiation effects
  • DNA Repair / physiology*
  • DNA Repair / radiation effects
  • DNA, Plant / chemistry*
  • DNA, Plant / genetics
  • DNA, Plant / metabolism
  • DNA, Single-Stranded / chemistry*
  • DNA, Single-Stranded / genetics
  • DNA, Single-Stranded / metabolism
  • Deoxyribodipyrimidine Photo-Lyase / chemistry*
  • Deoxyribodipyrimidine Photo-Lyase / genetics
  • Deoxyribodipyrimidine Photo-Lyase / metabolism
  • Protein Structure, Secondary / physiology
  • Protein Structure, Tertiary / physiology
  • Pyrimidine Dimers / chemistry*
  • Pyrimidine Dimers / metabolism
  • Ultraviolet Rays / adverse effects


  • Arabidopsis Proteins
  • Cryptochromes
  • DNA, Plant
  • DNA, Single-Stranded
  • Pyrimidine Dimers
  • Cry3 protein, Arabidopsis
  • Deoxyribodipyrimidine Photo-Lyase

Associated data

  • PDB/2VTB