"Alternating B-DNA" conformation for the oligo(dG-dC) duplex in high-salt solution.
"Alternating B-DNA" conformation for the oligo(dG-dC) duplex in high-salt solution.
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高盐溶液中寡聚 (dG-dC) 双链体的“交替 B-DNA”构象。
DOI：
10.1073/pnas.76.6.2508
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发表时间：
1979
影响因子：
11.1
通讯作者：
F. Pohl
中科院分区：
文献类型：
--
作者：
D. Patel;L. Canuel;F. Pohl
在低盐和高盐溶液中记录了(DG-DC)8双链的高分辨1H和31P核磁共振谱，以评估盐诱导的寡聚(DG-DC)在溶液中转变的结构[Pohl，F.M.&Jovin，T.M.(1972)J.Mol.比奥尔。67,375-396]。核磁共振数据要求(DG-DC)8双链在4M的氯化钠中采用“交替的B-DNA”构象，其对称单元每两个碱基对重复一次。相反，低盐溶液中的低聚物双链在溶液中为规则的B-DNA型。低聚糖(DG-DC)在高盐溶液中的化学位移参数表明，糖苷扭转角和磷酸二酯键的构象与常规B-DNA中观察到的构象不同。我们进一步证明，在嘧啶的5位引入卤素原子有助于“交替B-DNA”结构的产生，这可能反映了该位置与高盐溶液中相邻碱基对的更大重叠。基于pda-dt-da-dt[Klug，A.，Jack，A.，Viswamitra，M.A.，Kennard，O.，Shakked，Z.&Steitz，T.A.(1979)J.Mol]的X射线结构，最近提出了一种交替的脱氧嘌呤-脱氧嘧啶多核苷酸的B-DNA模型。生物，在新闻中]。
The high resolution 1H and 31P NMR spectra of the (dG-dC)8 duplex have been recorded in low- and high-salt solutions in order to evaluate the structural aspects of the salt-induced transition of oligo(dG-dC) in solution [Pohl, F. M. & Jovin, T. M. (1972) J. Mol. Biol. 67, 375-396]. The NMR data require that the (dG-dC)8 duplex in 4 M NaCl adopt an "alternating B-DNA" conformation for which the symmetry unit repeats every two base pairs. By contrast, the oligomer duplex in low-salt solution is of the regular B-DNA type in solution. The chemical shift parameters for oligo(dG-dC) in high-salt solution demonstrate that every other glycosidic torsion angle and phosphodiester linkage adopts a different conformation from that observed in regular B-DNA. We demonstrate further that the generation of the "alternating B-DNA" structure is facilitated by introduction of halogen atoms at the 5 position of pyrimidine and that this probably reflects the greater overlap of this position with adjacent base pairs in high salt solution. An "alternating B-DNA" model has recently been proposed for alternating deoxy purine-deoxy pyrimidine polynucleotides based on the x-ray structure of pdA-dT-dA-dT [Klug, A., Jack, A., Viswamitra, M.A., Kennard, O., Shakked, Z. & Steitz, T.A. (1979) J. Mol. Biol., in press].