Studies with Defined Deoxyribonucleic Acids

对非B DNA进行了体内和体外研究 包括分子内三链体和其他非B 在寡嘌呤的右旋构象。寡嘧啶束。 将对天然存在的pur.pyr序列进行研究 试图在原核生物中建立生物学功能， 真核细胞 此外，还将研究以下系统： 在某些基因座特异性克隆合成PUR.PYR片段， 试图阐明生物化学行为。 生物系统 包括复制和转录。 直接决定将 用于评价体内 质粒中的非B DNA寡聚嘌呤、寡聚嘧啶结构和 染色体 将使用几种探头，包括UV photofootprinting，KMnO 4和甲基化酶表达系统。 体外重点包括：阐明其他类型（非- 三链体）的非B DNA结构在pur。pyr道;条件， 稳定这些结构及其形成机制; 酶（如甲基化酶、限制性内切酶）作为构象异构酶， 探针;侧翼序列对热力学的影响， 动力学和结构; C残基甲基化的影响; 以及蛋白质的分离和表征， 特异性结合这些非B构象。 这些研究应该提供重要的洞察力， 发现的Pur.Pyr带的生物和化学特性 在许多重要的生物系统中。

In vivo and in vitro investigations are proposed on non-B DNA structures including intramolecular triplexes and other non-B right-handed conformations at oligopurine.oligopyrimidine tracts. Studies will be conducted on naturally occurring pur.pyr sequences to attempt to establish biological functions in prokaryotic and eukaryotic cells. Also, systems will be investigated where synthetic pur.pyr tracts are cloned specifically at certain loci to attempt to elucidate biochemical behaviors. Biological systems include replication and transcription. Direct determinations will be established to evaluate the existence and properties in vivo of non-B DNA oligopurine.oligopyrimidine structures in plasmids and chromosomes. Several probes will be utilized including UV photofootprinting, KMnO4, and methylase expression systems. In vitro emphases include: elucidation of other types (non- triplex) of non-B DNA structures at pur.pyr tracts; conditions which stabilize these structures and their mechanisms of formation; enzymes (such as methylases, restriction enzymes) as conformational probes; the effect of flanking sequences on thermodynamics, kinetics, and structures; the effect of methylation of C residues; and the isolation and characterization of proteins that specifically bind these non-B conformations. These studies should provide significant insight into the biological and chemical properties of pur.pyr tracts which are found in a variety of biologically important systems.