Interactions underlying assembly and function of TolC-dependent drug efflux and toxin export machineries

细菌性疾病对全世界的人类构成了不祥的威胁，造成了巨大的痛苦、死亡和经济损失。尤其是当我们现在看到新的致病菌株出现时，旧的菌株重新出现，因为它们对几十年来保护我们的抗生素的耐药性越来越强。因此，对抗生素进行复杂的研究比以往任何时候都更重要（？毒品？）了解细菌如何感染我们以及它们如何在抗生素治疗中存活。只有这样，我们才能找到新的方法来对付它们。在我们的实验室，我们结合联合收割机强大的实验方法来研究致病（致病）细菌的生物学。在这里，我们的目标是继续研究细菌在其复杂的细胞包膜中构建的大家族机制，以分泌蛋白质毒素，这些毒素作用于我们的细胞，并排出各种抗生素和其他有毒抑制剂（例如我们的胃胆汁盐）。因此，当细菌感染人类和动物宿主时，它们会增强细菌的存活，提高它们抵抗我们防御的能力，并有助于产生多药耐药性。这些毒力和耐药性机制是密切相关的，所有使用提供能量的转运复合体提供或？泵？它们的货物，无论是大蛋白质毒素或小抗生素，到一个细胞出口管称为TolC，我们已经表明渠道，他们走出细胞作为一个？垃圾道？然而，在分子水平上，这些机制在它们的特定组分和组分间相互作用的精细细节以及它们对特定底物的偏好方面也有显着差异。我们花了很多年的时间来描述这些医学上重要的和科学上有趣的机器，我们的工作最近成功地描述了常见的组件和它们的相互作用，这最终导致了一种称为AcrA-AcrB-TolC的完整组装的多药外排泵的第一个详细视图。现在，我们将利用我们来之不易的专业知识，将我们的重点转移到第二种重要类型的阻力泵（MacA-MacB-TolC）和毒素输出系统（HlyB-HlyD-TolC）上。这样我们就可以直观地看到这些？泵？在细菌细胞包膜中组装，识别共同的核心事件以及赋予它们功能灵活性的系统特异性变异。通过了解这些非凡的机器是如何组装和工作的，我们将更好地了解细菌感染我们的策略，并为我们打开新的方法来对抗它们。

Bacterial diseases present an ominous threat to humans throughout the world, causing great suffering, death, and economic cost. This is especially so as we now see new disease-causing strains emerging, and old ones re-emerging as they become increasingly resistant to the antibiotics that have protected us for decades. It is therefore more important than ever to perform sophisticated studies on antibiotic (?drug?) resistance and virulence mechanisms to learn how bacteria infect us and how they survive antibiotic treatment. Only then will we be able to see new ways to combat them. In our laboratory we combine powerful experimental approaches to study the biology of pathogenic (disease-causing) bacteria. Here we aim to continue our studies of the large family of machineries that bacteria build in their complex cell envelope to secrete protein toxins, which act on our cells, and expel a wide range of antibiotics and other noxious inhibitors (e.g. our stomach bile salts). They therefore enhance the survival of bacteria when they infect human and animal hosts, increasing their ability to counteract our defences and contributing to multidrug resistance. These virulence and drug resistance machineries are closely related, all using energy-providing transporter complexes to deliver or ?pump? their cargo, whether large protein toxins or small antibiotics, to a cell exit duct called TolC which we have shown channels them out of the cell as a ?trash chute?. However, at a molecular level the machineries also differ significantly in the fine detail of their specific components and inter-component interactions, and their preferences for particular substrates. We have spent many years characterizing these medically important and scientifically intriguing machineries, and our work has recently succeeded in describing the common components and their interactions, which culminated in the first detailed view of one type of complete assembled multidrug efflux pump called AcrA-AcrB-TolC. We will now exploit our hard-won expertise to shift our focus to achieving the same advance with a second important type of resistance pump (MacA-MacB-TolC), and a toxin export system (HlyB-HlyD-TolC). In this way we can visualize how these ?pumps? assemble in the bacterial cell envelope, identifying the common core events and also system-specific variations that give them such flexibility of function. By gaining a view of how these remarkable machines assemble and work, we will better understand the strategies bacteria employ to infect us, and will open new ways for us to counteract them.