CRYSTAL STRUCTURE OF THE COMPLEX OF PKR AND HIV TAR RNA

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。 我们的工作分为三个部分： a）PKR和HIV TAR RNA复合物的晶体学研究。 B）高分辨率HIV TAR结构的晶体学研究 c）IKK激酶复合物的晶体学研究。 人dsRNA活化蛋白激酶（PKR）是干扰素诱导基因的产物，是人先天防御系统的关键组分。 在病毒感染时，PKR通过丝氨酸51残基的磷酸化抑制翻译因子eIF-2a。PKR通过调节一些重要的转录因子参与转录。PKR激活的关键步骤是序列中dsRNA的相互作用，独立的方式。结合后，PKR经历构象重排和自磷酸化。本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-1 TAR dsRNA在体内和体外均可激活PKR，表现出dsRNA典型的浓度依赖性激活-抑制曲线。为了深入了解dsRNA：PKR相互作用的分子性质，PKR和TAR 57 RNA的复合物在C2空间群中结晶，细胞参数为：80.42，45.99，254.42 <$且a=90？00，B=97？。25和g=90？。00. 初步结果表明，在单位细胞中存在四个PKR分子，并可能存在两个PKR分子和一个TAR分子的组合物 157 RNA。 结果与中子散射研究的结果一致。

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 sequenceindependent 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.