PHYSICAL AND BIOLOGICAL PROTERTIES OF Z-DNA

Z-DNA，左手双螺旋，已经在晶体中看到， 合成聚脱氧核苷酸溶液。 有证据表明 Z-DNA也不在体内。 如果是这样的话，Z-DNA可能是基因的调节器， 表达，或者，由于其组成碱基的化学反应性， 一个重要的致癌物作用部位。 建议的目的 研究是为了更好地了解Z-DNA在物理上的现象， 和生物学水平，并最终理解DNA之间的关系 其生物学功能。 为了确定结构 稳定DNA的Z形式的参数，定义的序列 多聚脱氧核苷酸将通过化学和 生物化学方法，以及他们承担Z形式的能力将是 与它们的化学结构有关。 这是为了发展 能够预测在什么情况下任何特定的序列将 Z的形式。 此外，使用 当在闭环质粒中克隆时， 将对可能以Z形式存在的基因组DNA序列进行 以及与Z-DNA特异性结合的蛋白质。 这旨在 显示Z-DNA在体内的存在，或排除它作为一个普遍的 生物现象。 为上述目的而采取的方法 项目也将被用来寻找有关未回答的问题 DNA中的B-A转换，并检查发现的DNA序列的结构 在具有不同于本体核蛋白结构的真核生物中， 染色质

Z-DNA, the left handed double helix, has been seen in crystals and solutions of synthetic polydeoxynucleotides. Evidence exists that suggests Z-DNA is also not in vivo. If so, Z-DNA may be a regulator of gene expression or, because of the chemical reactivity of its constituent bases, an important site of carcinogen action. The purpose of the proposed research is to better understand the phenomenon of Z-DNA on both a physical and biological level, and ultimately to understand the relationship of DNA structure to its biological function. To determine the structural parameters stabilizing the Z form of DNA, defined sequence polydeoxynucleotides will be synthesized by a combination of chemical and biochemical methods, and their ability to assume the Z form will be correlated with their chemical structures. This is intended to develop the ability to predict under what circumstances any particular sequence will be in the Z form. Additionally, using the topological properties inherent in the left handed helix when cloned in closed circular plasmids, a search will be conducted for sequences of genomic DNA that can exist in the Z form and also for proteins that bind specifically to Z-DNA. This is intended to show the existence of Z-DNA in vivo, or to rule it out as a general biological phenomenon. The methods that will be in place for the above projects will also be used to look at unanswered questions concerning the B-A transition in DNA and to examine the structure of DNA sequences found in eukaryotes that have nucleoprotein structures different from bulk chromatin.