Bleomycin mediated degradation of DNA-RNA hybrids does not involve C-1' chemistry.
AUTOR(ES)
Absalon, M J
RESUMO
Incubation of Fe(II) bleomycin and O2 with a number of 'A'-like DNA-RNA hybrid homopolymers at 4 atm O2 results in formation of base propenal and base in a ratio of approximately 1.0:1.0. This ratio differs dramatically from the corresponding ratio of approximately 10:1.0 observed when activated BLM degrades 'B'-like DNA homopolymers. Experiments were undertaken to determine if the shift to enhanced base production observed in the A-like hybrids is the result of C-1' chemistry in addition to the C-4' chemistry normally observed with B-like DNA under identical conditions. Increased accessibility of the 1'-hydrogen might be anticipated due to widening of the minor groove in the A-like conformers. Experiments using poly([1'-3H]dA) poly(rU) and poly([U-14C]dA) poly(rU) indicated that neither 3H2O nor deoxyribonolactone accompanied adenine release. In addition, studies using poly([4'-2H]dA) poly(rU) and poly([1'-2H]dA) poly(rU) unambiguously establish that the altered base to base propenal ratio is not the result of C-1' chemistry, but a direct consequence of C-4' chemistry.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=334123Documentos Relacionados
- Effects of hypoxanthine substitution on bleomycin-mediated DNA strand degradation in DNA-RNA hybrids.
- Mechanistic analyses of site-specific degradation in DNA-RNA hybrids by prototypic DNA cleavers.
- Preparation of covalently linked DNA-RNA hybrids and arabinocytidine containing DNA fragments.
- Action of DNA Polymerase I of Escherichia coli with DNA-RNA Hybrids as Templates
- Assay of DNA-RNA hybrids by S1 nuclease digestion and adsorption to DEAE-cellulose filters.