DNA-Protein Interactions in Class III Genes

与DNA中特定碱基序列结合的蛋白质调节 许多不同基因的表达。 转录因子 TFIIIA是锌指蛋白质类的原型， 强烈地依赖于编码中包含的定义的碱基序列 5S RNA基因。 这种相互作用代表了 转录活性复合物组装的主要步骤 而且，一旦组装，这些复合物持续通过许多 轮的转录。 本研究的目的是 了解分子间的相互作用 在复合物形成过程中蛋白质及其靶序列， 转录。为了促进这些研究， 交联剂5-N3-脱氧尿苷-5 '- 三磷酸，可以酶促掺入DNA 代替胸苷。 光敏DNA可用于标记 蛋白质中的位点或区域， 纯化的TFIIIA和特异性DNA之间的接触 在Xenopus中的位置。 5S、DNA内部控制区 被映射。 这允许检查的精细结构， 这种相互作用来理解识别过程， 确定它是如何受到其他存在的影响， 转录因子以及RNA聚合酶III， 当聚合酶启动RNA时， 合成并穿过TFIIIA接触位点。

Proteins which bind to specific base sequences in DNA regulate the expression of many different genes. Transcription factor TFIIIA, the prototype of the Zn-finger class of proteins, binds strongly to a defined base sequence contained within the coding region of 5S RNA genes. This interaction represents the primary step in assembly of a transcriptionally active complex and, once assembled, these complexes persist through many rounds of transcription. The objective of this research is an understanding of the molecular interactions between this protein and its target sequence during complex formation and transcription. To facilitate these studies, a photosensitive cross-linking reagent has been developed, 5-N3-deoxyuridine-5'- triphosphate, which can be enzymatically incorporated into DNA in place of thymidine. Photoactive DNA can be used to label sites or regions in proteins which are in close proximity to the DNA, Contacts between purified TFIIIA and specific positions in the Xenopus. 5S, DNA internal control region have been mapped. This allows examination of the fine structure of this interaction to understand the recognition process, determine how it is affected by the presence of other transcription factors as well as RNA polymerase III, and look for changes which occur as the polymerase initiates RNA synthesis and traverses the TFIIIA contact sites.