Unravelling the rules of outer membrane protein folding: Opportunities for the design of new antibacterial strategies

外膜蛋白（OMPs）的折叠和组装是构建革兰氏阴性菌细胞壁所必需的。omp的序列如何使它们折叠到细菌的外膜中仍然未知，也不清楚基本的b桶组装机制（BAM）如何识别折叠的omp并将它们插入外膜（OM）。了解OMP折叠不仅具有巨大的基础意义，而且具有重要的翻译意义，因为靶向这一途径可能导致对抗革兰氏阴性病原体抗生素耐药性的新策略。在最近与David Baker (Seattle) （Science 2021）合作的基础上，我们成功设计了第一个合成的跨膜β桶蛋白，提供了一个独特的机会，可以在体外辅助/不辅助BAM的情况下，将从头设计的蛋白质的折叠机制与自然进化的蛋白质进行比较。该项目将确定：(i) omp序列如何在体外使其高效折叠成高度稳定的β -桶结构；（ii）哪些omp的序列/结构基序被BAM识别；（iii）细胞机制如何识别OMPS并将其靶向BAM折叠成OM。结果将是关于OMP如何折叠的新基础知识，BAM如何识别OMP的新见解，以及潜在的通过靶向OMP折叠对抗抗生素耐药性的新途径。

The folding and assembly of outer membrane proteins (OMPs) is essential to build the cell wall of gram-negative bacteria. How the sequences of OMPs enable their folding into the bacterial OM remains unknown, nor is it understood how the essential B-barrel assembly machinery (BAM), recognises folding OMPs and inserts them into the outer membrane (OM). Understanding OMP folding is not only of immense fundamental interest, but is translationally important as targeting this pathway could lead to new strategies to combat antibiotic resistance in gram-negative pathogens. Building on a recent collaboration with David Baker (Seattle) (Science 2021), we have successfully designed the first synthetic trans membrane beta barrel protein, providing a unique opportunity to compare the folding mechanisms of de novo designed proteins with their naturally evolved counterparts in vitro, and assisted/unassisted by BAM.This project will determine:(i) how the sequence of OMPs enables efficient folding to their highly-stable beta-barrel structures in vitro; (ii) which sequence/structural motifs of OMPs are recognised by BAM;(iii) how the cellular machinery recognizes OMPS and targets them to BAM for folding into the OM. The results will be new fundamental knowledge of how OMPs fold, new insights into how BAM recognises OMPs and potentially, new routs of combat antibiotic resistance by targeting OMP folding.