CRYSTAL STRUCTURE OF THE COMPLEX OF PKR AND HIV TAR RNA

这个子项目是利用由NIH/NCRR资助的中心拨款提供的资源的许多研究子项目之一。子项目和调查员(PI)可能从另一个NIH来源获得了主要资金，因此可能会出现在其他CRISE条目中。列出的机构是针对中心的，而不一定是针对调查员的机构。我们的工作分为三个部分：a)PKR与HIV TAR RNA复合物的结晶学研究。B)高分辨率HIV TAR结构的结晶学研究c)IKK激酶复合体的结晶学研究。人dsRNA激活的蛋白激酶(PKR)是干扰素诱导基因的产物，是人类先天防御系统的关键组成部分。作为对病毒感染的应答，PKR通过其丝氨酸51残基的磷酸化来抑制翻译因子eIF-2a。PKR通过调节一些重要的转录因子参与转录。PKR激活的一个关键步骤是dsRNA以序列无关的方式相互作用。结合后，PKR经历构象重排和自磷酸化。这项研究的长期目标是了解dsRNA的分子性质：PKR相互作用和蛋白激酶激活。HIV-1TAR dsRNA在体内和体外都能激活PKR，表现出典型的浓度依赖的激活-抑制曲线。为了深入了解dsRNA的分子性质：PKR相互作用，PKR与TAR 57RNA的复合物结晶在C2空间群中，晶胞参数为：80.42，45.99,254.42°，a=90？00，b=97？25，g=90？00。初步结果表明，在单位细胞中存在四个PKR分子，并可能由两个PKR分子和一个TAR？157RNA组成。这与中子散射研究的结果是一致的。

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. Our work is in three parts: a) Crystallographic study of complex of PKR and HIV TAR RNA. b) Crystallographic study of HIV TAR structure at high resolution c) Crystallographic study of IKK kinase complex. The human dsRNA activated protein kinase (PKR) is a product of an interferon-induced gene and a key component of the human innate defense system. In response to viral infection, PKR inhibits translation factor eIF-2a via phosphorylation of its serine 51 residue. PKR is involved in transcription by regulating some important transcription factors. A critical step in the activation of PKR is the interaction of dsRNA in a sequence¿independent manner. Upon binding, PKR undergoes conformational rearrangement and autophosphorylation. The long-term objective of this study is to understand the molecular nature of the dsRNA:PKR interaction and protein kinase activation. HIV-1 TAR dsRNA activates PKR both in vivo and in vitro, exhibiting a concentration-dependent, activation-inhibition curve typical of dsRNA To obtain insight into the molecular nature of dsRNA:PKR interaction, the complex of PKR and TAR 57 RNA was crystallized in a C2 space group with cell parameters: 80.42, 45.99, 254.42 ¿ and a=90?00, b=97?.25 and g=90?.00. The preliminary results indicate the presence of four PKR molecules in the unit cell and the possibility of a composition of two PKR molecules and one TAR ¿1 57 RNA. The results are consistent with those of the Neutron Scattering studies.