Partial Purification and Characterization of Uracil-DNA Glycosylase Activity from Chloroplasts of Zea mays Seedlings
AUTOR(ES)
Bensen, Robert J.
RESUMO
A uracil-DNA glycosylase activity has been purified about 750-fold from the chloroplasts of light-grown Zea mays seedlings. This report represents the first direct demonstration of a DNA-glycosylase repair activity in chloroplasts. The activity, in part, was associated with a chloroplast Triton X-100 sensitive membrane. Its apparent Km was 1.0 micromolar for a poly(dA-dT/U) substrate, and its molecular weight, as determined by gel filtration, was 18,000. The enzyme exhibited optimal activity at pH 7.0 with an atypically narrow pH tolerance. Activity was inhibited greater than 60% by 10 millimolar NaCl, 5 millimolar MgCl2, or 5 millimolar EDTA. Enzyme activity was inhibited 80% by 10 millimolar N-ethylmaleimide, a sulfhydryl group-blocking agent. The activity removed uracil more rapidly from single-stranded DNA than from double-stranded DNA. With this report, uracil-DNA glycosylase activity has now been attributed to all three DNA-containing organelles of eucaryotic cells.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1056735Documentos Relacionados
- The Partial Purification and Characterization of Nuclear and Mitochondrial Uracil-DNA Glycosylase Activities from Zea mays Seedlings 1
- Purification and characterization of a uracil-DNA glycosylase from the yeast. Saccharomyces cerevisiae.
- A mollicute (mycoplasma) DNA repair enzyme: purification and characterization of uracil-DNA glycosylase.
- Characterization of uracil-DNA glycosylase activity from Trypanosoma cruzi and its stimulation by AP endonuclease
- Uracil-DNA glycosylase of thermophilic Thermothrix thiopara.
