Administrative Equipment Supplement for Regulation and function of bacterial 100S ribosome

项目概要（来自父母奖） 在细菌蛋白质合成过程中，30 S和50 S核糖体亚基组装成 在模板mRNA上具有免疫活性的70 S核糖体。在革兰氏阳性人类细菌中， 病原体金黄色葡萄球菌，一种称为冬眠的小核糖体结合蛋白， 促进因子（SaHPF）刺激2.5-MDa 70 S单体的二聚化，形成 100 S复杂的沉默100 S核糖体的生理功能仍然存在 这是一个谜，因为100 S核糖体的时间丰度在不同的 在不同的细菌门中，100 S核糖体对翻译的全球影响是完全相同的。 未知，不同细菌的HPF无效突变体缺乏共同的表型。此外，远 相关的γ-变形菌，如E.大肠杆菌，需要两种蛋白质（EcRMF和EcHPF）， 实现100 S复合物形成。我们小组最近的数据表明，SaHPF是 在衰老的S.金黄色葡萄球菌细胞 令人惊讶的是，消除Sa_hpf仅引起翻译抑制基因的一个子集的去抑制。 入会仪式我们的目标是建立对100 S功能的机械理解 核糖体的翻译能力和葡萄球菌的发病机制。我们将采取多- 跨学科的方法，遗传学，分子生物物理学，生物化学，和整个动物 感染研究。目的1将确定可逆性的过程和因素 70 S和100 S核糖体的转化。目的2将确定SaHPF/100 S核糖体如何 以基因特异性方式抑制翻译。目标3将确定100 S综合体在以下方面的作用： 核糖体周转和葡萄球菌病理生理学。这些目标有可能产生 核糖体代谢的新见解，并激发了持续性和 复发性葡萄球菌感染与生存期延长密切相关 在宿主体内。

PROJECT SUMMARY (from the parental award) During bacterial protein synthesis, the 30S and 50S ribosomal subunits assemble into the translationally active 70S ribosome on template mRNA. In the Gram-positive human bacterial pathogen Staphylococcus aureus, a single small ribosome-binding protein called hibernation- promoting factor (SaHPF) stimulates the dimerization of 2.5-MDa 70S monomers to form the translationally silent 100S complex. The physiological function of the 100S ribosome remains enigmatic because the temporal abundance of the 100S ribosome varies considerably among different bacterial phyla, the global impact of the 100S ribosome on translation is completely unknown, and hpf null mutants of different bacteria lack a common phenotype. Moreover, distantly related gammaproteobacteria, such as E. coli, require two proteins (EcRMF and EcHPF) to achieve 100S complex formation. Recent data from our group demonstrate that SaHPF is essential for the bacterial survival and maintenance of the ribosome pool in aging S. aureus cells. Surprisingly, eliminating Sa_hpf causes the derepression of only a subset of genes at translational initiation. Our goal is to establish a mechanistic understanding of the function of the 100S ribosome in translational capacity and staphylococcal pathogenesis. We will take a multi- disciplinary approach that spans genetics, molecular biophysics, biochemistry, and whole animal infection studies. Aim 1 will determine the process and factors involved in the reversible conversion of 70S and 100S ribosomes. Aim 2 will determine how the SaHPF/100S ribosome inhibits translation in a gene-specific manner. Aim 3 will identify the roles of the 100S complex in ribosome turnover and staphylococcal pathophysiology. These aims have the potential to produce novel insights into ribosome metabolism and inspire alternate treatments for persistent and relapsed staphylococcal infections that are intimately linked to survive for an extended period inside the host.