NMR study of self‐paired parallel duplex of d(AAAAACCCCC) in solution

FEBS Letters

Luo, Jia¹  Sarma, Mukti H.¹  Yuan, Ren-da¹  Sarma, Ramaswamy H.¹ 

[1]Institute of Biomolecular Stereodynamics, State University of New York at Albany, NY 12222, USA

关键词: Oligonucleotide d(A5C5);    Self-parallel duplex;    Hemiprotonated;    2D NMR;    Computer modeling;   

DOI  :  10.1016/0014-5793(92)81005-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The oligonucleotide d(A₅C₅) in solution forms a parallel self-duplex at neutral and low pH values. H₂O NMR spectra at pH 5.1 indicate the presence of five imino resonances at lower temperatures; and the structure is stable up to 60°C. These signals ran arise only from the hemiprotonated C⁺·C pairs [Westhof, E. and Sundaralingham, M. (1980) Biochemistry 77, 1852–1856; Westhof, E. and Sundaralingham, M. (1980) J. Mol. Biol. 142, 331–361] and constitute the first direct observation of C⁺·C hemiprotonated pairs in solution. The cross peaks from Hl's and more than five distinct AH8's in 500 MHz ¹H 2D-NOESY spectra indicate that there are two conformationally different and energetically similar A-tracts. There is good qualitative agreement between NOESY data and two theoretically derived structures in which A-tracts are reverse Watson-Crick and reverse Hoogsteen base-paired, respectively.

【 授权许可】

Unknown