Molecular grammar of SurA-client interactions in the periplasm of gram-negative bacteria

革兰氏阴性菌周质中 SurA-客户相互作用的分子语法

• 批准号: BB/Y00034X/1
• 负责人: Antonio Calabrese
• 金额: $ 90.45万
• 依托单位: University of Leeds
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2024
• 资助国家: 英国
• 起止时间: 2024 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FY00034X%2F1
• 关键词: Molecular; grammar; SurA; client; interactions

Antibiotic resistance is projected to cause 10 million deaths per year by 2050, with gram-negative pathogens comprising 9 of the 12 bacteria that pose the greatest threat to human health, according to the World Health Organisation. These gram-negative pathogens have a unique outer membrane (OM) that acts as a first line of defence against an assault from potentially harmful molecules to the bacteria, such as antibiotics. As a result, the OM is essential for bacterial survival and is one reason why certain bacteria are resistant to different types of antibiotics. Finding ways to prevent correct assembly of the OM may therefore produce new routes to kill gram-negative bacteria, or make them more susceptible to existing antibiotics. However, the mechanism by with the OM is built remains mysterious, making its assembly difficult to target with therapeutics.Here we propose to determine how key proteins of the OM - so-called outer membrane proteins (or OMPs) - are folded into the OM to create the usually impenetrable cell wall. OMPs play essential roles in bacterial virulence and survival, so by understanding how OMPs are assembled into the OM it may be possible to develop new drugs that target this essential process. A key protein involved in ensuring OMPs reach the OM is a chaperone protein called SurA. SurA is an attractive target for the development of new drugs to control gram-negative pathogens because perturbing the chaperone function of SurA results in a loss of bacterial viability and virulence along with increased sensitivity to antibiotics. However, in order to target the chaperone function of SurA, further work is needed to understand its mechanism of action. We have recently discovered that two key sites on SurA are responsible for recognising OMPs. This is exciting, as it suggests that one or both of these sites could make good targets for new drug-like molecules. However, we still do not understand how each of these two binding sites contribute to OMP binding and chaperone function. Here we propose to use information from an array of complementary and cutting-edge experimental methodologies (including NMR spectroscopy, mass spectrometry, single molecular Forster resonance energy transfer, biochemistry/biophysics and bioinformatics) to understand how each of the newly discovered OMP binding sites on SurA recognises specific signals within its OMP clients. Further, we propose to determine how these two binding sites work together to bring about its chaperone function, in particular regarding SurA's role in protecting newly synthesised OMPs from aggregation and facilitating their delivery to the OM. This will uncover the molecular features of SurA that are essential for assisting in OMP biogenesis, which, in the future, could lead to new strategies to develop much-needed antibiotics that target gram-negative pathogens that threaten humans, plants and animals.

据世界卫生组织称，抗生素耐药性预计到2050年每年会导致1000万人死亡，革兰氏阴性病原体包括12种细菌中的9种，对人类健康构成最大威胁。这些革兰氏阴性病原体具有独特的外膜（OM），它是对潜在有害分子到细菌（例如抗生素）的攻击的第一道防线。结果，OM对于细菌生存至关重要，这是某些细菌对不同类型的抗生素具有抗性的原因之一。因此，寻找防止正确组装OM的方法可能会产生杀死革兰氏阴性细菌的新途径，或者使其更容易受到现有抗生素的影响。但是，OM建立的机制仍然神秘，这使得其组装很难用疗法靶向。在这里，我们建议确定OM的关键蛋白如何折叠到OM中，以创建通常不可渗透的细胞壁。 OMP在细菌毒力和生存中起着重要的作用，因此，通过了解如何将OMP组装到OM中，可以开发针对这一基本过程的新药物。确保OMP到达OM的关键蛋白质是一种称为Sura的伴侣蛋白。 Sura是开发新药以控制革兰氏阴性病原体的有吸引力的靶标，因为扰动Sura的伴侣功能会导致细菌生存能力和毒力丧失，并增加对抗生素的敏感性。但是，为了瞄准苏拉的伴侣功能，需要进一步的工作来了解其作用机理。我们最近发现，Sura上的两个关键站点负责识别OMP。这令人兴奋，因为这表明其中一个或两个可以为新药样分子带来良好的靶标。但是，我们仍然不了解这两个结合位点中的每个位点如何促进OMP结合和伴侣功能。在这里，我们建议使用来自一系列互补和尖端实验方法的信息（包括NMR光谱，质谱法，单分子福斯特福斯特共振能量传递，生物化学/生物物理学和生物信息学和生物信息学），以了解每个新发现的新发现的在Sura上识别其在Sura上识别其在其内部的绑定位点的信号。此外，我们建议确定这两个结合位点如何共同发挥其伴侣功能，尤其是关于Sura在保护新合成的OMP中的作用，并促进其向OM的递送。这将揭示Sura的分子特征，这些特征对于有助于OPM生物发生至关重要，这将来可能会导致新的策略来开发急需的抗生素，以靶向革兰氏阴性的病原体，从而威胁人类，动植物。