Isolation of active recombinant XPG protein, a human DNA repair endonuclease.
Complementation group G of xeroderma pigmentosum (XP-G) is one of the most rare and phenotypically heterogeneous forms of this inherited disorder. XP-G patients vary from having a very mild defect in DNA repair to being severely affected, and a few cases are also associated with the neurological complications of Cockayne's syndrome. The XPG gene encodes an acidic protein with a predicted molecular mass of 133 kDa that confers normal UV resistance when expressed in XP-G cells. Here we report the isolation of full-length XPG as a soluble protein expressed from a recombinant baculovirus. The purified polypeptide corrects the DNA nucleotide excision repair defect of XP-G cell extracts in vitro, and it acts as a magnesium-dependent single-stranded DNA endonuclease. This is the first direct evidence for a human protein with properties that implicate it in the incision step of nucleotide excision repair.
O'Donovan
A
A
Imperial Cancer Research Fund, Clare Hall Laboratories, South Mimms, Herts, United Kingdom.
Scherly
D
D
Clarkson
S G
SG
Wood
R D
RD
D000818:Animals; D016367:Baculoviridae / Q000235:genetics; D001483:Base Sequence; D004260:DNA Repair / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics*; D004720:Endonucleases / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D009036:Moths / Q000166:cytology; D009687:Nuclear Proteins; D000077183:Occlusion Body Matrix Proteins; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D014157:Transcription Factors; D014764:Viral Proteins / Q000235:genetics; D015678:Viral Structural Proteins; D014983:Xeroderma Pigmentosum / Q000145:classification / Q000201:enzymology / Q000235:genetics*; D000099250:DNA Excision Repair Protein ERCC-5
D004268:DNA-Binding Proteins; D004720:Endonucleases; D009687:Nuclear Proteins; D000077183:Occlusion Body Matrix Proteins; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D014764:Viral Proteins; D015678:Viral Structural Proteins; D000099250:DNA Excision Repair Protein ERCC-5; C009829:polyhedrin protein, Nucleopolyhedrovirus