STRUCTURE BASED DESIGN OF ANTI-INFECTIVE DRUGS

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。 随着耐药性细菌和病毒性疾病成为日益严重的世界卫生问题，迫切需要发现和开发新的抗感染药物。细菌核糖体是设计用于对抗细菌感染的氨基糖苷类抗生素的主要靶标。例如，抗生素如巴龙霉素和妥布霉素与16 S核糖体亚基内的RNA氨酰基解码位点（A位点）结合，并通过在蛋白质合成期间诱导错误编码来干扰翻译，这反过来导致细菌细胞的死亡。 丙型肝炎病毒（HCV）内部核糖体进入位点（IRES）元件在病毒基因组RNA的帽非依赖性翻译中起着核心作用。IRES结构域II的独特构象对于80 S核糖体组装和病毒翻译的起始至关重要。在这里，HCV IRES的亚结构域IIa的晶体结构已被确定在2.3 A分辨率，揭示了二价金属离子和复杂的链间相互作用，稳定的RNA的L形构象的位置。二价金属离子的存在是晶体形成所必需的。镁离子占据的特定网站，似乎是关键的折叠构象的形成。亚结构域IIa也在锶的存在下结晶，这提高了晶体的衍射质量和鉴定RNA与金属离子和紧密结合的水分子的相互作用的能力。铰链区和非典型的G-U碱基对基序被二价金属离子稳定，并提供独特的结构特征，这些结构特征是小分子配体的潜在相互作用位点。从晶体结构中获得的信息提供了一个基础的HCV翻译抑制剂靶向破坏核糖体组装的结构导向设计。这项工作发表在Acta Cryst. D。

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. The discovery and development of new anti-infective drugs is urgently needed, as drug-resistant bacterial and viral diseases become an increasingly serious world health problem. The bacterial ribosome is a primary target of aminoglycoside antibiotics designed to combat bacterial infection. For instance, antibiotics such as paromomycin and tobramycin bind to the RNA aminoacyl decoding site (A-site) within the 16S ribosomal subunit and interfere with translation by inducing miscoding during the protein synthesis, which in turn leads to the death of the bacterial cell. The hepatitis C (HCV) internal ribosome entry site (IRES) element plays a central role in cap-independent translation of the viral genomic RNA. The unique conformation of IRES domain II is critical for 80S ribosomal assembly and initiation of viral translation. Here, the crystal structure of subdomain IIa of the HCV IRES has been determined at 2.3 A resolution, revealing the positions of divalent metal ions and complex inter-strand interactions that stabilize the L-shaped conformation of the RNA. The presence of divalent metal ions was necessary for crystal formation. Magnesium ions occupy specific sites that appear to be critical for the formation of the folded conformation. Subdomain IIa also was crystallized in the presence of strontium, which improved the diffraction quality of the crystals and the ability to identify interactions of the RNA with metal ions and tightly bound water molecules. The hinge region and noncanonical G-U base-pair motifs are stabilized by divalent metal ions and provide unique structural features that are potential interaction sites for small-molecule ligands. The information obtained from the crystal structure provides a basis for structure-guided design of HCV translation inhibitors targeting disruption of ribosomal assembly. This work was published in Acta Cryst. D.