The Drosophila ortholog of the human XPG gene.
Xeroderma pigmentosum complementation group G (XPG) protein is a junction-specific endonuclease which is indispensable for nucleotide excision repair (NER) of DNA in eukaryotes. Recent studies have hinted at a second, essential function for the XPG protein in higher eukaryotes. We undertook a comparison of the amino acid sequences of multiple XPG orthologs to determine if a motif or domain could be identified that is conserved uniquely in higher eukaryotes. A search of current databases allowed us to retrieve complete amino acid sequences for the human, mouse and Xenopus XPG proteins, and for two yeast orthologs. We also identified an incomplete Drosophila open reading frame (ORF) that was a good candidate for the XPG protein. We cloned a complete Drosophila cDNA for this ORF and examination of the primary amino acid sequence suggests that this cDNA encodes the Drosophila ortholog of XPG. A comparison of all six orthologous polypeptides reveals the presence of two previously unidentified conserved domains. One of these is unique to all four higher eukaryotic sequences. Conceivably this domain evolved to support the essential function of XPG protein.
Laboratory of Molecular Pathology, Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX 75235-9072, USA.
J F
JF
Houle
E C
EC
Friedberg
D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D003001:Cloning, Molecular; D017124:Conserved Sequence / Q000235:genetics; D004247:DNA / Q000737:chemistry / Q000235:genetics; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics*; D004331:Drosophila melanogaster / Q000737:chemistry / Q000235:genetics*; D004720:Endonucleases; D005057:Eukaryotic Cells / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D009687:Nuclear Proteins; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors; D000099250:DNA Excision Repair Protein ERCC-5
D004247:DNA; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D004720:Endonucleases; D009687:Nuclear Proteins; D014157:Transcription Factors; D000099250:DNA Excision Repair Protein ERCC-5