ANALYSIS OF AN OLIGO(DA) OLIGO(DT) BINDING PROTEIN

描述（改编自申请人摘要）：关键控制点 在转录过程中可以由DNA结合蛋白控制， 基因组内的少量靶点。 这些具体的研究 反式作用因素导致了对许多调节的洞察， 细胞过程，包括控制细胞周期进程的过程，以及 正常和异常的生长和分化。 知之甚少 关于蛋白质与高度重复的DNA元件的特定相互作用 以及这些相互作用对转录的影响。 简单的非交替序列dA.dT在许多情况下高度重复， 有机体 这一序列，已被证明采取了不寻常的 构象，促进酵母中的转录。 已经提出 这种转录激活与 dA.dT.研究人员最近报告说发现了一种新的酵母 与非交替dA. dT特异性相互作用的DNA结合蛋白。 该蛋白（datin）已被纯化，其基因（DAT 1）已被克隆。 更 最近的研究表明，Datin可以负调控 含有上游dA、dT片段的基因。 此外，Datin还可以 正调控其自身的表达（datin的启动子含有dA、dT 序列）。 由于许多酵母启动子含有dA.dT片段，这些 观察表明，Datin可以调节大的表达， 基因的数量。 这是本提案中所述的两个主要目标。 一是 研究人员将确定Datin结合的分子基础 dA.dT.具体而言，研究者将定义不同形式的 存在于体内的DNA，这些不同的精确的DNA元件 Datin的形式与Datin相互作用，Datin中的氨基酸残基 是这种互动的必要条件。 研究人员还将尝试 生成Datin/oligo（dA）。(dT)用于X射线衍射研究的晶体。 其次，研究者将确定哪些生理功能， 达丁群岛 具体而言，研究者将确定 Datin对基因的转录调控作用， 上游dA.dT片段，并鉴定和表征额外的基因， 编码与DAT 1的功能重叠的功能。 这些研究不会 只会有助于理解 负责特定的DNA/蛋白质相互作用，但也将有助于 对基因表达调控的理解。

DESCRIPTION (Adapted from applicant's abstract): Critical control points in transcription can be governed by DNA binding proteins that recognize small numbers of targets within the genome. Studies of these specific trans-acting factors have led to insights into the regulation of many cellular processes including those that govern cell cycle progression, and normal and aberrant growth and differentiation. Relatively little is known about specific interactions of proteins with highly repeated DNA elements and the transcriptional influences that these interactions can exert. The simple nonalternating sequence dA.dT is highly repeated in many organisms. This sequence, which has been shown to adopt an unusual conformation, promotes transcription in yeast. It has been proposed that this transcriptional activation is related to the unique structure of dA.dT. The investigator recently reported the discovery of a new yeast DNA-binding protein that specifically interacts with nonalternating dA.dT. This protein (datin) has been purified, and its gene, (DAT1) cloned. More recent work shows that datin can negatively regulate the expression of genes which contain upstream dA.dT tracts. In addition, datin is able to positively regulate its own expression (datin's promoter contains dA.dT sequences). Since many yeast promoters contain dA.dT tracts, these observations suggest that datin can modulate the expression of large numbers of genes. These are two major objectives described in this proposal. First, the investigator will determine the molecular basis by which datin binds to dA.dT. Specifically the investigator will define the different forms of datin which exist in vivo, the precise DNA elements that these different forms of datin interact with, and the amino acid residues in datin which are necessary for this interaction. The investigator will also attempt to generate datin/oligo(dA).(dT) crystals for x-ray diffraction studies. Second, the investgator will determine what the physiological functions of datin are. Specifically, the investigator will determine the transcriptional regulatory effects that datin exerts on genes which contain upstream dA.dT tracts, and identify and characterize additional genes which encode functions that overlap the function of DAT1. These studies will not only contribute to the understanding of the molecular mechanisms responsible for specific DNA/protein interactions, but will also contribute to the understanding of the regulation of gene expression.