CRYSTALLOGRAPHIC STUDIES OF THE LACTOSE REPRESSOR

乳糖操纵子已成为研究基因调控的范式。 到 更全面地了解操纵子是如何调节的， （1）lac阻遏物的晶体结构测定，（2） 阻遏物与诱导物结合，（3）阻遏物形成三元复合物 合成操纵基因DNA片段加上抗诱导剂 三 这种蛋白质的三维结构和复合物将使我们能够 处理以下问题： (1)阻遏物如何识别DNA上的特定位点？ (2)诱导剂和反诱导剂是如何影响 阻遏物？ (3)结构在变构机制中起什么作用， 用来调节基因表达的基因吗 此外，lac阻遏物的三维结构将 提供了一个框架，用于关联和解释大量的 基因和化学数据。

The lactose operon has served as the paradigm to study gene regulation. To understand more completely how the operon is regulated we have undertaken the crystallographic structure determination of (1) the lac repressor, (2) the repressor bound to inducer and (3) the repressor in a ternary complex with synthetic operator fragments of DNA plus an anti-inducer. The three dimensional structure of this protein and the complexes will allow us to address such questions as: (1) How does the repressor recognize specific sites on the DNA? (2) How do the inducers and anti-inducers affect the conformation of the repressor? (3) What role does structure play in the allosteric mechanism and how is it used to regulate gene expression? In addition, the three dimensional structure of the lac repressor will provide a framework for correlating and interpreting an extensive body of genetic and chemical data.