XPG endonuclease makes the 3' incision in human DNA nucleotide excision repair.
Humans with a defect in the XPG protein suffer from xeroderma pigmentosum (XP) resulting from an inability to perform DNA nucleotide excision repair properly. Here we show that XPG makes a structure-specific endonucleolytic incision in a synthetic DNA substrate containing a duplex region and single-stranded arms. One strand of the duplex is cleaved at the border with single-stranded DNA. A cut with the same polarity is also made in a bubble structure, at the 3' side of the centrally unpaired region. Normal cell extracts introduce a nick 3' to a platinum-DNA lesion, but an XP-G cell extract is defective in making this incision. These data show that XPG has a direct role in making one of the incisions required to excise a damaged oligonucleotide, by cleaving 3' to DNA damage during nucleotide excision repair.
O'Donovan
A
A
Imperial Cancer Research Fund, Clare Hall Laboratories, South Mimms, Herts, UK.
Davies
A A
AA
Moggs
J G
JG
West
S C
SC
Wood
R D
RD
D001483:Base Sequence; D004260:DNA Repair; D004277:DNA, Single-Stranded / Q000378:metabolism; D004268:DNA-Binding Proteins; D004706:Endodeoxyribonucleases; D004720:Endonucleases / Q000378:metabolism*; D004926:Escherichia coli; D005656:Fungal Proteins / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D011994:Recombinant Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology; D029701:Saccharomyces cerevisiae Proteins; D014983:Xeroderma Pigmentosum / Q000201:enzymology* / Q000235:genetics
D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; C073998:RAD2 protein, S cerevisiae; D004706:Endodeoxyribonucleases; D004720:Endonucleases; C023141:DNA-specific endonuclease (xeroderma pigmentosum)