Human uracil DNA N-glycosidase: studies in normal and repair defective cultured fibroblasts.
AUTOR(ES)
Kuhnlein, U
RESUMO
Uracil DNA N-glycosidase, an enzyme which participates in the excision of uracil from DNA, was measured in extracts from fibroblasts lines cultured from normal subjects, from several subjects with the genetic disease xeroderma pigmentosum, and from a subject with ataxia telangiectasia. The cell lines representative of complementation groups A and D of xeroderma pigmentosum and of ataxia telangiectasia had roughly the same level of activity as did the normal cells. On the other hand, cells from two xeroderma pigmentosum variants (XP4BE and XP13BE) had roughly half the normal level of activity, and cells from the heterozygous mother of XP4BE had an intermediate level of activity. In spite of these quantitative differences, no systematic alterations in reaction characteristics, apparent Km for substrate, or purification characteristics were noted for enzyme from any of the lines. Thus a causal relationship, if any, between levels of activity and the disease symptoms is equivocal.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=341965Documentos Relacionados
- Deoxyuridine residues in DNA of thymine-requiring Bacillus subtilis strains with defective N-glycosidase activity for uracil-containing DNA.
- Isolation and Characterization of a Bacillus subtilis Mutant with a Defective N-Glycosidase Activity for Uracil-Containing Deoxyribonucleic Acid
- An N-Glycosidase from Escherichia coli That Releases Free Uracil from DNA Containing Deaminated Cytosine Residues
- Enzymatic degradation of uracil-containing DNA. II. Evidence for N-glycosidase and nuclease activities in unfractionated extracts of Bacillus subtilis.
- Different rate-limiting steps in excision repair of ultraviolet- and N-acetoxy-2-acetylaminofluorene-damaged DNA in normal human fibroblasts.
