DNA STRUCTURE AND GENE REGULATION

将从分子水平研究基因调控的机制。 特别强调DNA性质和构象的作用 专一性的决定因素。左撇子DNA的特性将是 用已知序列和重组的限制性片段进行研究 质粒。碱基序列对区域能力的影响 形成左手螺旋的研究将用合成的DNA聚合物来进行， 含有简单重复序列(天然和 合成起源)和在结构上确定序列的突变体 有趣的片段。促进R向L过渡的条件(如 作为离子环境，超螺旋，鸟苷部分的AAF修饰， 和甲基化)将被调查。将尝试确定 左撇子和左撇子的结合处的结构和化学行为 Z区和一个右手B段。它在生物学上的意义 左撇子DNA将在体外和体内进行评估。 构象性质将由圆二向色性、质子 和磷核磁共振，激光拉曼光谱以及超螺旋 重组分子拓扑异构体的密度测定。X射线 衍射研究将在合作的基础上进行。基因 克隆将被广泛用于制备化学定义的 具有具有所需序列的插入的分子。毫克量 用高压液体对限制性片段插入片段进行纯化 RPC-5的层析 对基因表达细节的理解是我们 最终理解正常的细胞生长和分裂以及 以不受控制的生长为特征的疾病综合征，如癌症。

The mechanism of gene regulation at the molecular level will be studied with special emphasis on the role of DNA properties and conformations as determinants of specificity. The properties of left-handed DNA will be investigated with restriction fragments of known sequence and recombinant plasmids. The influence of base sequence on the capacity of a region to form a left-handed helix will be studied with synthetic DNA polymers, plasmids containing simple repeating sequences (both of natural and synthetic origin) and with mutants of defined sequence in the structurally interesting segments. Conditions that promote the R to L transition (such as ionic environment, supercoiling, AAF modification of guanosine moieties, and methylation) will be investigated. Attempts will be made to determine the structure and chemical behavior of the junction between a left-handed Z-region and a right-handed B-segment. The biological significance of left-handed DNA will be evaluated in vitro and in vivo. Conformational properties will be determined by circular dichroism, proton and phosphorus NMR, and laser Raman spectroscopy as well as superhelix density determinations on topoisomers of the recombinant molecules. X-ray diffraction studies will be pursued on a collaboratilve basis. Gene cloning will be employed extensively to prepare chemically defined molecules with inserts with the desired sequences. Milligram quantities of the restriction fragment inserts will be purified by high pressure liquid chromatography on RPC-5 An understanding of the details of gene expression is fundamental to our ultimate comprehension of normal cellular growth and divison as well as disease syndromes characterized by unregulated growth such as cancer.