Rich A, Nordheim A, Azorin F
Department of Biology, Massachusetts Institute of Technology, Cambridge 02139.
J Biomol Struct Dyn. 1983 Oct;1(1):1-19. doi: 10.1080/07391102.1983.10507424.
Left-handed Z-DNA is favored by nucleotide sequences with alternating purines and pyrimidines. The structural basis of this preference is described, as well as the factors which stabilize Z-DNA. The most important biological factors stabilizing Z-DNA are negative supercoiling and Z-DNA binding proteins. Experiments are described which make it possible to determine the nucleotide sequences of segments which form Z-DNA through the use of specific antibodies. Parts of the plasmid pBR322 form Z-DNA upon negative supercoiling. Similarly, three segments of the SV40 simian tumor virus form Z-DNA. They are located in the transcriptional enhancer region and may function, together with Z-DNA binding proteins, in facilitating the attachment of RNA polymerase to the DNA in chromatin. This is the first specific example suggesting a role of Z-DNA in regulating transcription.
左手螺旋的Z-DNA受嘌呤和嘧啶交替排列的核苷酸序列的青睐。文中描述了这种偏好的结构基础以及稳定Z-DNA的因素。稳定Z-DNA的最重要生物学因素是负超螺旋和Z-DNA结合蛋白。文中还描述了一些实验，这些实验通过使用特异性抗体，能够确定形成Z-DNA的片段的核苷酸序列。质粒pBR322的部分区域在负超螺旋作用下形成Z-DNA。同样，猿猴病毒SV40的三个片段也形成Z-DNA。它们位于转录增强子区域，可能与Z-DNA结合蛋白一起，在促进RNA聚合酶与染色质中的DNA结合方面发挥作用。这是表明Z-DNA在调节转录中起作用的第一个具体例子。
