Sobell H M, Tsai C C, Gilbert S G, Jain S C, Sakore T D
Proc Natl Acad Sci U S A. 1976 Sep;73(9):3068-72. doi: 10.1073/pnas.73.9.3068.
Conformational changes in DNA that accompany drug intercalation have led us to ask if DNA first bends or "kinks" to accept an intercalative drug or dye. Kinking is made possible by altering the normal C2' endo deoxyribose sugar ring puckering in B DNA to a mixed sugar puckering pattern of the type C3' and partially unstacking base-pairs. A kinking scheme such as this would require minimal stereochemical 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 nucleic acids. In this papter we describe an interesting superhelical DNA structure formed by kinking DNA every 10 base-pairs. The structure may be used in the organization of DNA in chromatin.
药物嵌入过程中伴随的DNA构象变化促使我们思考，DNA是先弯曲还是“扭结”以接纳嵌入性药物或染料。通过将B型DNA中正常的C2'内式脱氧核糖糖环褶皱改变为C3'类型的混合糖环褶皱模式并使部分碱基对解堆叠，扭结成为可能。这样的扭结方案所需的立体化学重排最少，且能量消耗也小。这促使我们更广泛地思考，蛋白质在与核酸相互作用时是否可以利用这种构象变化。在本文中，我们描述了一种有趣的超螺旋DNA结构，该结构通过每隔10个碱基对使DNA扭结而形成。这种结构可能用于染色质中DNA的组织。
