TY - JOUR
T1 - Repair by human cell extracts of single (6-4) and cyclobutane thymine-thymine photoproducts in DNA
AU - Szymkowski, David E.
AU - Lawrence, Christopher W.
AU - Wood, Richard D.
PY - 1993/11/1
Y1 - 1993/11/1
N2 - One cis-syn cyclobutane thymine dimer or one (6-4) thymine-thymine photoproduct was built into an identical sequence of a closed-circular M13 duplex DNA, and nucleotide excision repair synthesis carried out by human cell extracts in the area containing each lesion was determined. Extracts from normal cells repaired the (6-4) photoproduct with a patch size of ≈20-30 nucleotides, but repair was at least 10-fold lower at the cyclobutane dimer. The (6-4) lesion was repaired with comparable efficiency to a single acetylaminofluorene-guanine adduct in a similar location. Extract from nucleotide excision repair-deficient xeroderma pigmentosum group A cells could not remove any of these adducts but could complete repair of the lesions after incision with Escherichia coli UvrABC proteins. This direct comparison of repair of two UV photoproducts, in an in vitro system where chromatin assembly and transcription are absent, suggests that the more rapid repair of the (6-4) lesion observed in the mammalian cell genome overall is due in part to a significant difference in the ability of the repair complex to locate and incise these lesions in DNA.
AB - One cis-syn cyclobutane thymine dimer or one (6-4) thymine-thymine photoproduct was built into an identical sequence of a closed-circular M13 duplex DNA, and nucleotide excision repair synthesis carried out by human cell extracts in the area containing each lesion was determined. Extracts from normal cells repaired the (6-4) photoproduct with a patch size of ≈20-30 nucleotides, but repair was at least 10-fold lower at the cyclobutane dimer. The (6-4) lesion was repaired with comparable efficiency to a single acetylaminofluorene-guanine adduct in a similar location. Extract from nucleotide excision repair-deficient xeroderma pigmentosum group A cells could not remove any of these adducts but could complete repair of the lesions after incision with Escherichia coli UvrABC proteins. This direct comparison of repair of two UV photoproducts, in an in vitro system where chromatin assembly and transcription are absent, suggests that the more rapid repair of the (6-4) lesion observed in the mammalian cell genome overall is due in part to a significant difference in the ability of the repair complex to locate and incise these lesions in DNA.
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U2 - 10.1073/pnas.90.21.9823
DO - 10.1073/pnas.90.21.9823
M3 - Article
C2 - 8234319
AN - SCOPUS:0027505049
SN - 0027-8424
VL - 90
SP - 9823
EP - 9827
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 21
ER -