DNA-sequence and metal-ion specificity of the formation of *H-DNA.
AUTOR(ES)
Bernués, J
RESUMO
The homopyrimidine-homopurine sequence d(CT/GA)22 undergoes, in the presence of zinc ions, transition to an altered DNA conformation (*H-DNA) which is neither H-DNA nor B-DNA. *H-DNA is characterized by a peculiar chemical reactivity pattern in which most of the polypyrimidine strand is hyperreactive to osmium tetroxide and the central part of the polypurine strand is sensitive to diethylpyrocarbonate. Formation of *H-DNA is specific of metal-ion. *H-DNA is detected in the presence of Zn++, Cd++ and Mn++. The efficiency on promoting the transition is in the order of Zn++ greater than Cd++ much greater than Mn++. Formation of *H-DNA is also specific of nucleotide sequence. From all the different homopolymeric sequences tested only the d(CT/GA)22 sequence showed the zinc-induced transition to *H-DNA. These results suggest that stabilization of *H-DNA involves the formation of a specific complex between the metal-ion and the nucleotide sequence. The biological relevance of these results is discussed in view of the important role that zinc ions play on many nucleic acids processes.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=331161Documentos Relacionados
- 2-Aminopurine fluorescence studies of base stacking interactions at abasic sites in DNA: metal-ion and base sequence effects.
- Brownian-dynamics simulations of metal-ion binding to four-way junctions
- A possible mechanism for metal-ion induced DNA-protein dissociation in a family of prokaryotic transcriptional regulators.
- Conversion of agonist site to metal-ion chelator site in the β2-adrenergic receptor
- Two-dimensional protein crystallization via metal-ion coordination by naturally occurring surface histidines.