title: Defective thymine dimer excision by cell-free extracts of xeroderma pigmentosum cells.
abstract: Crude extracts of normal human diploid fibroblasts and of human peripheral blood lymphocytes excise thymine dimers from purified ultraviolet-irradiated DNA, or from the DNA presumably present as chromatin in unfractionated cell-free preparations of cells that had been labeled with [3H]thymidine. Extracts of xeroderma pigmentosum cells from complementation groups A, C, and D also excise thymine dimers from purified DNA, but extracts of group A cells do not excise dimers from the DNA of radioactively labeled unfractionated cell-free preparations.
mesh_terms: D002460:Cell Line; D002843:Chromatin / Q000378:metabolism; D004247:DNA / Q000528:radiation effects; D004260:DNA Repair; D004269:DNA, Bacterial / Q000378:metabolism; D005347:Fibroblasts; D006801:Humans; D008214:Lymphocytes / Q000378:metabolism; D011830:Radiation Effects; D013941:Thymine / Q000378:metabolism*; D014466:Ultraviolet Rays; D014983:Xeroderma Pigmentosum / Q000235:genetics / Q000378:metabolism*
chemical_list: D002843:Chromatin; D004269:DNA, Bacterial; D004247:DNA; D013941:Thymine