STRUCTURE & INTERACTIONS OF THE CLP PROTEASE SYSTEM: FOLDING & DEGRADATION

Clp蛋白酶系统是蛋白质的重要组成部分 在细菌和植物质体中的代谢。 它包括 ClpP蛋白酶，其本身可能在大多数细胞上是无活性的， 生理底物和ATP酶的ClpA家族， 将底物呈递给ClpP。 CIP系统发挥着重要作用 细菌和植物中蛋白质的ATP依赖性周转，但可能 还起到方便运输、折叠、 激活一些蛋白质。 因此，该系统可以代表 细胞折叠途径中的重要决定点， 降解 我们正在研究ClpP和ClpA的三名成员 E.大肠杆菌（ClpA、ClpB和ClpX）中， 和由克隆基因表达的工程蛋白质。 以前我们 证明了E. coliClpP是一个21.5kDa亚单位的十四聚体。 最近，我们已经生长出了晶体的ClpP， 分辨率 我们建议确定其三维结构。 ClpP的高分辨率结构可以为以下方面提供重要线索： a）丝氨酸蛋白酶作用机制的细节，B）线索， ClpP的变构调节的性质，以及c）有助于 了解ATP在脑缺血机制中的作用 蛋白酶

The Clp protease system is an important element in protein metabolism in both bacteria and plant plastids. It consists of the ClpP protease, which by itself is probably inactive on most physiological substrates, and the ClpA family of ATPases, which present substrates to CIpP. The CIp system plays a major role ATP-dependent turnover of proteins in bacteria and plants, but may also play a role in facilitating the transport, folding, and activation of some proteins. This system may, therefore, repre sent an important decision point in the cellular pathway of folding and degradation. We are studying ClpP and three members of the ClpA family of ATPases from E. coli (ClpA, ClpB, and ClpX) using wild type and engineered proteins expressed from cloned genes. Previously we demonstrated that E. coli ClpP is a tetradecamer of 21.5kDa subunits'. Recently, we have grown crystals of ClpP that diffract to 2.2A resolution. We propose to determine its three-dimensional structure. A high resolution str ucture of ClpP may provide important clues into: a) the details of mechanism of action of serine proteases, b) clues to the nature of the allosteric regulation of ClpP, and c) aid in understanding the requirement of ATP in the mechanism of the CIp protease.