title: Surviving the sun: repair and bypass of DNA UV lesions.
abstract: Structural studies of UV-induced lesions and their complexes with repair proteins reveal an intrinsic flexibility of DNA at lesion sites. Reduced DNA rigidity stems primarily from the loss of base stacking, which may manifest as bending, unwinding, base unstacking, or flipping out. The intrinsic flexibility at UV lesions allows efficient initial lesion recognition within a pool of millions to billions of normal DNA base pairs. To bypass the damaged site by translesion synthesis, the specialized DNA polymerase η acts like a molecular "splint" and reinforces B-form DNA by numerous protein-phosphate interactions. Photolyases and glycosylases that specifically repair UV lesions interact directly with UV lesions in bent DNA via surface complementation. UvrA and UvrB, which recognize a variety of lesions in the bacterial nucleotide excision repair pathway, appear to exploit hysteresis exhibited by DNA lesions and conduct an ATP-dependent stress test to distort and separate DNA strands. Similar stress tests are likely conducted in eukaryotic nucleotide excision repair.
authors: Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Rm. B1-03, Bethesda, Maryland 20892, USA. Wei.Yang@nih.gov
authors: Wei
authors: W
authors: Yang
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D004247:DNA / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D004249:DNA Damage; D004265:DNA Helicases / Q000378:metabolism; D004260:DNA Repair / Q000235:genetics*; D059371:DNA, B-Form / Q000737:chemistry; D004268:DNA-Binding Proteins / Q000378:metabolism; D004255:Deoxyribodipyrimidine Photo-Lyase / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000378:metabolism; D006801:Humans; D009690:Nucleic Acid Conformation; D011740:Pyrimidine Dimers / Q000378:metabolism; D013472:Sunlight / Q000009:adverse effects*; D014466:Ultraviolet Rays / Q000009:adverse effects*
chemical_list: D059371:DNA, B-Form; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D011740:Pyrimidine Dimers; C058093:UvrB protein, E coli; D004247:DNA; C068631:UvrA protein, E coli; D000251:Adenosine Triphosphatases; D004265:DNA Helicases; D004255:Deoxyribodipyrimidine Photo-Lyase