Sobell H M, Tsai C C, Jain S C, Sakore T D
Philos Trans R Soc Lond B Biol Sci. 1978 May 11;283(997):295-8. doi: 10.1098/rstb.1978.0027.
X-ray crystallographic studies of drug-nucleic acid crystalline complexes have suggested that DNA first bends or 'kinks' before accepting an intercalative drug or dye. This flexibility in DNA structure is made possible by altering the normal C2' endo deoxyribose sugar puckering in B DNA to a mixed sugar puckering pattern of the type C3' endo (3'-5') C2' endo and partially unstacking base pairs. A kinking scheme such as this would require minimal sterochemical rearrangement and would also involve small energies. This has prompted us to ask more generally if a conformational change such as this could be used by proteins in their interactions with DNA. Here we describe an interesting superhelical DNA structure formed by kinking DNA every ten base pairs. This structure may be used in the organization of DNA within the nucleosome structure in chromatin.
对药物 - 核酸晶体复合物的X射线晶体学研究表明，DNA在接受嵌入性药物或染料之前首先会弯曲或“扭结”。DNA结构的这种灵活性是通过将B型DNA中正常的C2'内型脱氧核糖糖环化改变为C3'内型（3'-5'）C2'内型的混合糖环化模式并使部分碱基对解堆叠来实现的。这样的扭结方案需要最小的立体化学重排，并且也涉及较小的能量。这促使我们更普遍地询问，蛋白质在与DNA相互作用时是否可以利用这种构象变化。在这里，我们描述了一种有趣的超螺旋DNA结构，它是由每隔十个碱基对使DNA扭结而形成的。这种结构可能用于染色质核小体结构内DNA的组织。
