Clore G M, Gronenborn A M
FEBS Lett. 1984 Sep 17;175(1):117-23. doi: 10.1016/0014-5793(84)80582-7.
Using the proton-proton nuclear Overhauser effect, a large number (150) of interproton distances, both intra- and internucleotide, are determined in solution for a non-self-complementary DNA undecamer comprising a portion of the specific target site for the cAMP receptor protein in the gal operon. It is shown that these distances are very similar to those expected for classical B DNA (RMS difference of 0.5 A) but are significantly different from those expected for classical A DNA (RMS difference 1.1A). Glycosidic (chi) and C4'-C3' (delta) bond torsion angles are obtained by model building on the basis of the intranucleotide interproton distances. Whereas the sugar pucker exhibits little base-to-base variation with delta lying in the range 120 +/- 10 degrees, the glycosidic bond torsion angles of the pyrimidine and purine residues are significantly different, with chi pyr = -120 +/- 10 degrees and chi pur = -90 +/- 10 degrees.
利用质子-质子核Overhauser效应，在溶液中确定了一个非自互补DNA十一聚体（包含gal操纵子中cAMP受体蛋白特定靶位点的一部分）内大量（150个）质子间距离，包括核苷酸内和核苷酸间的距离。结果表明，这些距离与经典B型DNA预期的距离非常相似（均方根差异为0.5 Å），但与经典A型DNA预期的距离显著不同（均方根差异为1.1 Å）。糖苷键（χ）和C4'-C3'（δ）键扭转角是根据核苷酸内质子间距离通过模型构建获得的。虽然糖环构象在碱基间变化很小，δ值在120°±10°范围内，但嘧啶和嘌呤残基的糖苷键扭转角显著不同，χ嘧啶 = -120°±10°，χ嘌呤 = -90°±10°。
