STRUCTURE OF NATURALLY FOLDED APOPTOSIS INDUCING FACTOR

这个子项目是许多研究子项目中的一个 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来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 含有FAD的哺乳动物细胞凋亡诱导因子（AIF）是一种遗传学上古老的半胱天冬酶非依赖性死亡效应物，其通常存在于线粒体膜间隙中，但在细胞凋亡诱导后易位至细胞核并触发染色质凝聚和大规模DNA片段化。虽然有强有力的证据表明AIF与自由基稳态和氧化应激有关，但这种蛋白质诱导的细胞凋亡的生理功能和机制都不清楚。到目前为止，只有截断，重折叠形式的致突变AIF的晶体结构是可用的。我们发现，重折叠和截断显着扰动的氧化还原特性的黄素蛋白。因此，获得结构信息的自然折叠，？健康吗AIF的形式对于理解线粒体中蛋白质的结构/功能关系和生理作用至关重要。我们获得了AIF的天然折叠催化结构域（残基77-612）的衍射良好的晶体，但由于大的单元尺寸，X射线模型的当前分辨率被限制为3.2英寸，检测器尺寸限制。我们的目标是通过收集2 θ角设置为10-20 °的同步加速器数据来扩展分辨率。

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 FAD-containing mammalian apoptosis inducing factor (AIF) is a phylogenetically old caspase-independent death effector that normally resides in the mitochondrial intermembrane space but upon apoptosis induction translocates to the nucleus and triggers chromatin condensation and large scale DNA fragmentation. Although there is strong evidence that AIF is linked to free radical homeostasis and oxidative stress, neither physiological function nor mechanism of apoptosis induced by this protein is known. To date, only the crystal structures of truncated, refolded forms of apoptogenic AIF are available. We found that refolding and truncation significantly perturb the redox properties of the flavoprotein. Thus, obtaining structural information on naturally folded, ?healthy? form of AIF is vital for understanding structure/function relationships and the physiological role of the protein in mitochondria. We obtained well-diffracting crystals of the naturally folded catalytic domain of AIF (residues 77-612) but owing to large cell dimensions the current resolution of the x-ray model is limited to 3.2 ¿, the detector size limit. We aim to extend the resolution by collecting the synchrotron data with the 2-theta angle set to 10-20¿.