Dickerson R E, Drew H R, Conner B N, Wing R M, Fratini A V, Kopka M L
Science. 1982 Apr 30;216(4545):475-85. doi: 10.1126/science.7071593.
Recent advances in DNA synthesis methods have made it possible to carry out single-crystal x-ray analyses of double-stranded DNA molecules of predetermined sequence, with 4 to 12 base pairs. At least one example has been examined from each of the three known families of DNA helix: A, B, and Z. Each family has its own intrinsic restrictions on chain folding and structure. The observed solvent positions in these crystal structures have confirmed earlier fiber and solution measurements, and have led to proposals explaining the transitions from B to A and from B to Z helices. Prospects are improving for an understanding of the mode of bending of DNA in chromatin, and the way in which specific DNA sequences are recognized by drug molecules and repressor proteins.
DNA合成方法的最新进展使得对具有4至12个碱基对的预定序列的双链DNA分子进行单晶X射线分析成为可能。已从三个已知的DNA螺旋家族（A、B和Z）中各检测了至少一个实例。每个家族在链折叠和结构方面都有其自身固有的限制。在这些晶体结构中观察到的溶剂位置证实了早期的纤维和溶液测量结果，并引发了关于从B型螺旋向A型螺旋以及从B型螺旋向Z型螺旋转变的解释提议。对染色质中DNA弯曲模式以及药物分子和阻遏蛋白识别特定DNA序列方式的理解前景正在改善。
