Formation of a parallel-stranded DNA homoduplex by d(GGA) repeat oligonucleotides.
AUTOR(ES)
Suda, T
RESUMO
The GGA9-H molecules consisting of a double helical stretch followed by a single-stranded 3'-terminal overhang of nine GGA sequence repeats exhibited a gel mobility-shifted band in a concentration-dependent manner, suggestive of the intermolecular complex formation. The position of the shifted band in a gel was almost identical to that of the Y-shaped dimer marker of the same molecular weight that had the two double-helices at one side. This suggests that GGA9-H dimerizes in a parallel orientation without the formation of four-stranded hairpin structure. Since the GGA9-H homoduplex was stably formed at pH 4, 7 and 9, the formation does not require protonation or deprotonation of the N1 position of adenines. Neither does it require the N7 group of guanines responsible for Hoogsteen base pairing from the methylation interference and modification studies. Modification of the N7 group of guanines with dimethyl sulfate (DMS) did not inhibit the association and also the N7 group in the homoduplex was not protected from DMS. On the other hand, the GAA9-H having the G to A base substitution did not show such an association with either GGA9-H or GAA9-H. These results suggest that the homoduplex formation may be due to G.G base pairing through non-Hoogsteen hydrogen bonds.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=307278Documentos Relacionados
- Alternating d(G-A) sequences form a parallel-stranded DNA homoduplex.
- A novel activity of HMG domains: promotion of the triple-stranded complex formation between DNA containing (GGA/TCC)11 and d(GGA)11 oligonucleotides.
- Hairpin-dimer equilibrium of a parallel-stranded DNA hairpin: formation of a four-stranded complex.
- NMR structure of a parallel-stranded DNA duplex at atomic resolution
- Structure and drug interactions of parallel-stranded DNA studied by infrared spectroscopy and fluorescence.