STUDIES ON STRUCTURAL HOMOLOGUES, PUTIDAREDOXIN REDUCTASE & APOPTOSIS INDUCING F

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。本文将采用晶体学方法确定两种结构同源的含fad酶的三维结构，并研究它们的结构/功能关系，这两种酶分别是来自恶臭假单胞菌的putidaredoxin reductase （Pdr）和来自小鼠的凋亡诱导因子（AIF）。两种黄蛋白都有谷胱甘肽还原酶折叠，具有双功能。Pdr在细胞色素P450cam单加氧酶中催化NADH向铁硫蛋白putidaredoxin的电子转移，但它也具有氧化还原活性半胱氨酸，并可作为二硫醇/二硫化物氧化还原。AIF是一种古老的哺乳动物，不依赖于caspase的死亡效应物，在细胞凋亡诱导下，它从正常定位线粒体膜间隙转移到细胞核，在那里它导致染色质凝聚和DNA断裂。该蛋白诱导细胞凋亡的生理功能和机制尚不清楚。我们的研究解决了Pdr和AIF的结构如何与其催化功能相关的问题。

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. A crystallographic approach will be used to determine three-dimensional structures and study structure/function relationships in two structurally homologous FAD-containing enzymes, putidaredoxin reductase (Pdr) from Pseudomonas putida and apoptosis inducing factor (AIF) from mice. Both flavoproteins have a glutathione reductase fold and are bifunctional. Pdr catalyzes electron transfer from NADH to an iron-sulfur protein, putidaredoxin, in cytochrome P450cam monooxygenase, but it also has redox active cysteines and can function as dithiol/disulfide oxidoreduction. AIF is a phylogenetically old mammalian, caspase-independent death effector which, upon apoptosis induction, translocates from its normal localization, the mitochondrial intermembrane space, to the nucleus where it causes chromatin condensation and DNA fragmentation. Neither physiological function nor mechanism of apoptosis induced by this protein is known. Our research addresses the question of how the structures of Pdr and AIF are related to their catalytic function.