STRUCTURAL STUDIES ON PROTEINS THAT CONTROL APOPTOSIS, SULFUR ASSIMILATION & NEU

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。子项目及 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。 SSRL需要时间对来自三种不同生物系统的蛋白质进行高分辨率结构测定。 一个系统涉及抑制细胞凋亡的病毒蛋白。 在这个更新的建议中，我的实验室正在积极地进行病毒蛋白和细胞半胱天冬酶之间复合物的结构测定，它们抑制。 我们最近已经生长了分裂前和分裂后复合物的晶体，它们在光束线9-1上的分辨率分别为5和4.6。 我们目前正在进行实验，以增加晶体的顺序，以改善衍射。 第二个系统涉及将环境中的无机硫同化到生物体内的蛋白质。 我们最近确定了酶ATP硫酸化酶的结构，它催化硫同化的第一个承诺步骤，从两个不同的物种。 我们现在将采用定点突变来产生突变体，以研究结构-功能关系，以了解变构调节以及研究这些酶从人类。 需要时间的最后一个系统是PLP依赖性酶γ-氨基丁酸转氨酶。 这种酶是用于治疗癫痫、亨廷顿病、精神分裂症和阿尔茨海默病的神经活性药物的重要靶标。我们解决了E。大肠杆菌酶的结构，并将研究与药物和抑制剂复合的抑制结构方面。 SSRL的高通量将以更高的分辨率获得更高质量的数据，并能够更好地了解这三个系统中的所有蛋白质结构。

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. Time is requested at SSRL for high-resolution structure determination of proteins from three different biological systems. One system involves viral proteins that inhibit apoptosis. In this proposal renewal, my laboratory is actively pursuing structure determination of complexes between the viral protein and the cellular caspases, which they inhibit. We recently have grown crystals both of the pre- and post-cleavage complex that diffract to 5¿ and 4.6¿ resolution respectively on beam line 9-1. We are currently pursuing experiments to increase the order in the crystals to improve diffraction. The second system involves proteins that assimilate inorganic sulfur from the environment into living organisms. We have recently determined the structure of the enzyme ATP sulfurylase, which catalyzes the first committed step in sulfur assimilation, from two different species. We will now be employing site-directed mutagenesis to create mutants to study structure-function relationships to understand the allosteric regulation as well as study these enzymes from human. The last system for which time is requested is on a PLP dependent enzyme gamma-aminobutyrate aminotransferase. This enzyme is an important target for neuroactive drugs used in treatment of epilepsy, Huntington's disease, schizophrenia and Alzheimer's disease. We have solved the E. coli enzyme structure and will study structural aspects of inhibition complexed with drugs and inhibitors. The high flux from SSRL will result in higher quality data at much higher resolution and enable better more detailed understanding for all the protein structures in these three systems.