Structural studies of Antibiotic-ribosome complexes

蛋白质合成是在称为核糖体的大分子机器上进行的。蛋白质合成的本质使其成为细菌中抗菌剂的主要靶点。然而，多重耐药细菌的增加正在使我们目前的武器库过时，而新抗生素，特别是那些具有新支架的抗生素的批准迅速下降，使这个问题更加严重。到目前为止，大多数与临床相关的抗生素的可用结构是(I)在空置的核糖体亚基上，(Ii)中等分辨率(3.0-3.5Aangstrom)，以及(Iii)仅限于少数细菌种类。在这项提案中，我们建议通过提供对控制小分子与RNA相互作用的规则的关键见解来重新激活基于结构的核糖体抑制剂的设计。为此，我们将确定抗生素-核糖体复合体的结构(I)以前所未有的分辨率(亚2 Aangtstrom)，其中可以看到水分子、离子甚至氢，(Ii)在生理相关的功能状态中，(Iii)来自不同的细菌物种，包括致病的ESKAPE细菌，以及(Iv)包含具有新的结合位点和/或支架的化合物，以限制交叉耐药性。此外，这些研究不仅将提供对抑制剂的作用机制的洞察，而且还将提供对蛋白质合成本身的基本过程的深入了解。

Protein synthesis is performed on macromolecular machines called ribosomes. The essential nature of protein synthesis makes it a major target for antimicrobial agents in bacteria. However, the increase in multi-drug resistant bacteria is making our current arsenal of obsolete, and this problem is compounded by the rapid decline in the approval of new antibiotics, particularly those with novel scaffolds. To date, the majority of the available structures of clinically-relevant antibiotics are (i) on vacant ribosomal subunits, (ii) at modest resolution (3.0-3.5 Aangstrom), and (iii) are restricted to a few bacterial species. In this proposal, we propose to re-invigorate the structure-based design of ribosome inhibitors by providing critical insight into the rules governing small molecule interaction with RNA. To do this, we will determine structures of antibiotic-ribosome complexes (i) at unprecedented resolution (sub-2Aangtstrom), where water molecules, ions and even hydrogens can be visualized, (ii) within physiologically-relevant functional states, (iii) from diverse bacterial species, including pathogenic ESKAPE bacteria, as well as (iv) encompassing compounds with novel binding sites and/or scaffolds to limit cross-resistance. Additionally, these studies will not only provide insight into the mechanism of action of the inhibitors, but also into the fundamental process of protein synthesis itself.