Publication Abstract from PubMed
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.
Recognition and repair of UV lesions in loop structures of duplex DNA by DASH-type cryptochrome.,Pokorny R, Klar T, Hennecke U, Carell T, Batschauer A, Essen LO Proc Natl Acad Sci U S A. 2008 Dec 30;105(52):21023-7. Epub 2008 Dec 12. PMID:19074258[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
