CHAPERONE STRUCTURE/FUNCTION PROTEIN FOLDING

描述：分子伴侣由一组不同的蛋白质组成 它们在帮助蛋白质折叠和组装方面发挥重要作用，在 蛋白质跨膜运输和蛋白质复性和/或 防止由于各种类型的压力而导致的聚集。一个 提出了多方面的研究方案，以研究其功能和 约70 kDa(Hsp79)类分子的结构 和他们的共同监护人。 建议的研究重点是Hsc66和Hsc20，新的伴侣和 与(2Fe-2S)铁氧还蛋白共同编码的辅伴蛋白 最近在大肠杆菌中发现了操纵子。新的发现表明 Hsc66和Hsc20在铁氧还蛋白的折叠和/或组装中的作用 和其他铁硫蛋白，以及遗传和 建议用生化方法来研究Hsc66和Hsc66的作用。 Hsc20和伴侣蛋白相互作用的机制。高性能的系统 Hsc66和Hsc2的高效表达和纯化 为了能够表征其催化和多肽结合特性 天然蛋白质和定点突变体的蛋白质。 还提出了Hsc66和Hsc20的结构研究。Hsc20的晶体 和天然蛋白质(1.9A)的X-射线衍射数据。 重原子衍生物(2.2a)产生了一个初步的电子 用于建模和结构优化的密度贴图。适用的条件 Hsc66的结晶正在开发中。这些研究的结果 应有助于更好地了解伴侣功能和 结构，它们应该为细胞机制提供新的见解 参与铁硫蛋白的折叠和组装，以及 对这些过程的监管。

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.