STUDIES OF CRYO-COOLING AND CATALYTIC MECHANISM IN E COLI BETA-GALACTOSIDASE

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。三个实验描述涉及大肠杆菌β -半乳糖苷酶，旨在解决三个广泛相关的主题。首先是通过了解-半乳糖苷酶晶体中低温诱导的重包装来提高我们对低温的基本认识。其次是了解包装力如何通过表征配体结合的差异来调节酶的活性，从而在不对称单元中分离亚基。第三是了解构象开关在-半乳糖苷酶活性中的作用以及填充力如何影响这种开关。每个实验在原理上都很简单，但考虑到电池的大尺寸，技术要求很高。变体和配合物的结构将以1.1¿¿分辨率确定。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Three experiments are described involving E. coli beta-galactosidase designed to address three broadly related topics. First is to improve our basic knowledge about cryocooling by understanding the cryocooling induced repacking in crystals of beta-galactosidase. Second is to understand how packing forces modulate enzyme activity by characterizing differences in ligand binding to separate subunits in an asymmetric unit. And third is to understand the role of a conformational switch in the activity of beta-galactosidase and how packing forces affect this switch. Each experiment is straightforward in principle, but technically demanding given the large size of the unit cell. Structures of variants and complexes will be determined up to 1.1 ¿¿resolution.