CHAPERONE STRUCTURE/FUNCTION PROTEIN FOLDING

描述：分子伴侣包括一组不同的蛋白质 在帮助蛋白质折叠和组装中起着重要作用， 蛋白质跨膜转运和蛋白质复性和/或 防止由于各种类型的压力而导致的聚集。 一 多方面的研究计划，提出了调查的功能， 约70 kDa（hsp 79）类分子伴侣的成员的结构 和他们的共同监护人 拟议的研究集中在Hsc 66和Hsc 20，新的伴侣蛋白， 与（2Fe-2S）铁氧还蛋白一起编码的辅伴侣蛋白在一个 最近在大肠杆菌中发现了操纵子。 新发现表明 Hsc 66和Hsc 20在铁氧还蛋白的折叠和/或组装中起作用 和其他铁硫蛋白。大肠杆菌，以及遗传和 提出了生物化学方法来研究Hsc 66和 hsc 20与分子伴侣-蛋白质相互作用的机制。 系统为高 已经开发了Hsc 66和Hsc 2的水平表达和用于纯化 以允许表征的催化和肽结合性能的 天然蛋白质和位点特异性突变体。 对Hsc 66和Hsc 20的结构进行了研究。 Hsc 20晶体 已经获得，并且天然蛋白质的X射线衍射数据（1.9A） 和一个重原子衍生物（2.2A）产生了一个初级电子 用于建模和结构细化的密度图。 条件 Hsc 66的结晶正在开发中。 这些研究的结果 应该导致更好地了解伴侣蛋白的功能， 结构，他们应该提供新的见解细胞机制 参与铁硫蛋白的折叠和组装， 这些过程的规范。

DESCRIPTION: Molecular chaperoned comprises a diverse group of proteins which play important roles in assisting protein folding and assembly, in protein transport across membranes, and protein renaturation and/or prevention of aggregation as a result of various types of stress. A multi-faceted research program is proposed to investigate the function and structure of members of the approximately 70kDa (hsp79) class of chaperoned and their co-chaperones. The proposed studies focus on Hsc66 and Hsc20, novel chaperone and co-chaperone proteins encoded together with a (2Fe-2S) ferredoxin in a recently discovered operon in Escherichia coli. New findings suggest that Hsc66 and Hsc20 function in the folding and/or assembly of the ferredoxin and other iron-sulfur proteins in E. coli, and a combination of genetic and biochemical approaches are proposed to investigate the roles of Hsc66 and Hsc20 and the mechanism of chaperone-protein interactions. Systems for high level expression and for purification of Hsc66 and Hsc2 have been developed to allow characterization of the catalytic and peptide binding properties of the native proteins and of site-specific mutants. Structural studies on Hsc66 and Hsc20 are also proposed. Crystals of Hsc20 have been obtained, and x-ray diffraction data on the native protein (1.9A) and a heavy atom derivative (2.2A) have yielded a preliminary electron density map for modeling and structural refinement. Conditions for crystallization of Hsc66 are being developed. The results of these studies should lead to better general understanding of chaperone function and structure, and they should provide new insights into cellular mechanisms involved in the folding and assembly of iron-sulfur proteins and the regulation of these processes.