title: Domains in the XPA protein important in its role as a processivity factor.
abstract: XPA is a protein essential for nucleotide excision repair (NER) where it is thought to function in damage recognition/verification. We have proposed an additional role, that of a processivity factor, conferring a processive mechanism of action on XPF and XPG, the endonucleases, involved in NER. The present study was undertaken to examine the domain(s) in the XPA gene that are important for the ability of the XPA protein to function as a processivity factor. Using site-directed mutagenesis, mutations were created in several of the exons of XPA and mutant XPA proteins produced. The results showed that the DNA binding domain of XPA is critical for its ability to act as a processivity factor. Mutations in both the zinc finger motif and the large basic cleft in this domain eliminated the ability of XPA to confer a processive mechanism of action on the endonucleases involved in NER.
authors.affiliation: Department of Pathology and Laboratory Medicine, UMDNJ-New Jersey Medical School, Newark, NJ 07103, USA.
authors.forename: Claudine L
authors.initials: CL
authors.lastname: Bartels
authors.forename: Muriel W
authors.initials: MW
authors.lastname: Lambert
mesh_terms: D001665:Binding Sites; D002460:Cell Line; D004247:DNA / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects; D004249:DNA Damage; D004260:DNA Repair / Q000235:genetics / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000378:metabolism; D004720:Endonucleases / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D009687:Nuclear Proteins / Q000378:metabolism; D011485:Protein Binding; D011994:Recombinant Proteins / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D014466:Ultraviolet Rays; D051760:Xeroderma Pigmentosum Group A Protein / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D000099250:DNA Excision Repair Protein ERCC-5
chemical_list: D004247:DNA; D004268:DNA-Binding Proteins; D004720:Endonucleases; D009687:Nuclear Proteins; D011994:Recombinant Proteins; D014157:Transcription Factors; D051760:Xeroderma Pigmentosum Group A Protein; D000099250:DNA Excision Repair Protein ERCC-5; C095888:xeroderma pigmentosum group F protein