Role of DNA Binding Linked Protein-Protein Interactions in Gene Regulation

DNA 结合连接的蛋白质-蛋白质相互作用在基因调控中的作用

基本信息

批准号：
9513661
负责人：
Donald Senear
金额：
$ 8.68万
依托单位：
University of California-Irvine
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
1996
资助国家：
美国
起止时间：
1996-09-01 至 1998-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=9513661&HistoricalAwards=false
关键词：
Role DNA Binding Linked Protein

项目摘要

9513661 Senear Sequence specific binding of regulatory proteins to unique DNA sites is the basis for regulation of transcriptional initiation. These studies are involved with the roles of protein-protein interactions in mediating these processes. One aim is to determine how dimer self-assembly and coupled interactions mediate DNA binding cooperativity. Dimers can self-assemble in solution to form octamers as the immediate product. Tetramers, the species long believed to mediate pairwise cooperativity, are minor intermediates in a concerted reaction. Therefore, coupled interactions are responsible for selecting a minor component of the solution species distribution as a major component of the DNA-bound distribution, hence as critical to regulation. By investigating the thermodynamic cycles that couple repressor self-assembly to operator binding, one can determine what solution assembly contributes to cooperativity and what protein and DNA mediated coupling contribute. A second aim addresses how protein-protein interactions contribute to differential affinity of repressor dimers for the three OR operator sites. It is now well established that the separate subunits that bind the two halves of the pseudo-palindromic operators do not interact independently with DNA. Coupling between the individual subunit-half site interactions involves both repressor and DNA conformational changes. Correlating structural and chemical changes resulting in the dimer interface with effects on dimer stability and operator binding specificity will lead to an understanding of the mechanisms of inter-subunit communication and protein structural changes that contribute to differential operator affinity. ***

9513661 Senear 序列调节蛋白与独特 DNA 位点的特异性结合是转录起始调节的基础。这些研究涉及蛋白质-蛋白质相互作用在介导这些过程中的作用。目的之一是确定二聚体自组装和耦合相互作用如何介导 DNA 结合协同性。二聚体可以在溶液中自组装形成八聚体作为直接产物。四聚体，长期以来被认为能够介导成对协同性，是协同反应中的次要中间体。因此，耦合相互作用负责选择溶液物种分布的次要成分作为 DNA 结合分布的主要成分，因此对于调节至关重要。通过研究将阻遏物自组装与操纵子结合耦合的热力学循环，人们可以确定哪种溶液组装有助于协同性以及蛋白质和 DNA 介导的偶联有何贡献。第二个目标是解决蛋白质-蛋白质相互作用如何影响阻遏物二聚体对三个 OR 操纵子位点的不同亲和力。现在已经确定，结合伪回文算子两半的单独亚基不会独立地与 DNA 相互作用。各个亚基-半位点相互作用之间的耦合涉及阻遏物和 DNA 构象变化。将导致二聚体界面的结构和化学变化与二聚体稳定性和操纵子结合特异性的影响相关联，将有助于理解亚基间通讯的机制和有助于差异操纵子亲和力的蛋白质结构变化。 ***