EVOLUTION OF J-PROTEINS

该子项目是利用 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得主要资金， 因此可以在其他CRISP条目中表示。列出的机构是 中心，不一定是研究者的机构。 生物体已经进化出一种专门的多组分蛋白质系统，以确保正确的FeS簇组装。 该系统包括Fe和S供体、Fe/S簇组装的支架以及促进Fe/S簇转移过程的Hsp 70分子伴侣和J蛋白辅助分子伴侣。 虽然在大多数真核生物中，Hsp 70也参与其他过程，如蛋白质折叠和输入，但在细菌和一小部分真菌中，它已进化为仅在Fe/S簇组装中起作用。 作为分子共同进化的结果，这些生物体中的J蛋白辅助分子伴侣也变得更加特化。 然而，这种专业化的确切性质仍然未知。 我们假设，cochaperones之间的结构差异是部分负责，并使用NMR光谱来确定和彻底比较J蛋白的结构，从一个生物体与一般的热休克蛋白70和一个生物体与一个专门的热休克蛋白70。 我们希望我们的研究结果将进一步支持我们的假设。

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. Organisms have evolved a specialized, multi-component protein system to ensure correct FeS cluster assembly. This system includes Fe and S donors, a scaffold for the Fe/S cluster assembly and an Hsp70 chaperone and a J protein cochaperone to facilitate the Fe/S cluster transfer process. While in most eukaryotes the Hsp70 also participates in other processes such protein folding and import, in bacteria and a small subset of fungi it has evolved to function in Fe/S cluster assembly only. As a result of molecular coevolution, the J protein cochaperone in these organisms also became more specialized. The exact nature of this specialization remains unknown however. We hypothesize that structural differences among the cochaperones are partly responsible and are using NMR spectroscopy to determine and thoroughly compare the structures of J proteins from an organism with a general Hsp70 and an organism with a specialized Hsp70. We hope the results of our studies will lend further support to our hypothesis.