Genetic and Biochemical Studies of the Tryptophan Operon

将作出重大努力，以了解分子 详细描述了色氨酸阻遏物与， 这个阻遏物控制的三个操纵子的操纵子 将使用突变体进行结构-功能研究 阻遏物 这些研究应阐明结构 色氨酸结合位点的要求， 二聚体的形成和异源二聚体的性质， 的氨基末端臂，和之间的关系， 螺旋E的氨基酸序列，DNA识别序列 阻遏物，并在三个识别碱基对 运营商 此外，第二次研究中心恢复研究将 进行各种突变类型的分析 阻遏物内的补偿相互作用， 阻遏物不同区域的功能改变。 将继续进行生理学研究， 更好地了解trp基因调控如何发生在生长 细胞 色氨酸合成酶进化的研究 将继续关注基因重排， 基因融合发生在进化的单一 酵母和脉孢菌色氨酸合成酶多肽 分离的细菌多肽。

A major effort will be made to understand the molecular details of trp repressor interaction with, and regulation of, the operators of the three operons this repressor controls. Structure-function studies will be performed using mutant repressors. These studies should elucidate the structural requirements of the tryptophan binding site, the process of dimer formation and the properties of heterodimers, the role of the amino terminal arm, and the relationship between the amino acid sequence of helix E, the DNA-recognition sequence of the repressor, and recognized base pairs in the three operators. In addition, second site reversion studies will be carried out with various mutant classes to analyze compensating interactions within the repressor and functional alterations in different regions of the repressor. Physiological studies will be continued in an effort to better understand how trp gene regulation occurs in growing cells. Studies on the evolution of tryptophan synthetase will continue and will focus on the gene rearrangement and gene fusion that occurred in the evolution of the single tryptophan synthetase polypeptide of yeast and Neurospora from the separate polypeptides of bacteria.