Investigating the role of YhdP and other AsmA-like proteins in phospholipid transport in gram-negative bacteria

革兰氏阴性菌由于其外膜的复杂结构而对当前抗生素具有较高的抗性。该膜充当亲水性分子和小疏水性分子（包括抗生素和洗涤剂）的不可渗透屏障。不对称的外膜分别由内小叶和外小叶中的磷脂和LPS组成，虽然对LPS合成和转运的理解已经很好地理解，但磷脂在膜之间的运动令人惊讶地未知。最近，内膜蛋白YhdP已被牵连在高通量磷脂运输，已被证明延迟MlaA* 突变体的细胞死亡表型，突变体，通过破坏脂质不对称性（Mla）途径的维持引起内膜破裂。此外，E. yhdP缺失的大肠杆菌细胞具有较弱的外膜，并且对SDS+EDTA和万古霉素的敏感性增加。YhdP是AsmA样蛋白家族的成员，具有共同的AsmA样结构域，因此可能具有相似的功能。该项目将研究YhdP和其他AsmA样蛋白，即AsmA，TamB，YhjG，YicH和YdbH，以确定它们在革兰氏阴性细菌外膜生物合成中的作用。将采用涉及生物化学、生物物理学和分子生物学技术的多学科方法，包括X射线晶体学、中子反射计和低温电子显微镜。该项目将有助于我们对这一神秘过程的现有知识，并可能导致发现新的抗生素靶点，以应对抗生素耐药性上升的公共卫生威胁。

Gram-negative bacteria have an elevated resistance to current antibiotics due to the sophisticated architecture of their outer membrane. This membrane acts as an impermeable barrier to hydrophilic molecules and small hydrophobic molecules including antibiotics and detergents. The asymmetric outer membrane is composed of phospholipids and LPS in the inner and outer leaflets respectively, and whilst understanding of LPS synthesis and transport is well understood, the movement of phospholipids between the membranes is surprisingly unknown. Recently, the inner membrane protein YhdP has been implicated in high-flux phospholipid transport, having been shown to delay the cell death phenotype of MlaA* mutants, a mutant that causes inner membrane rupture by disrupting the maintenance of lipid asymmetry (Mla) pathway. Additionally, E. coli cells with a yhdP deletion have a weaker outer membrane and increased sensitivity to SDS+EDTA and vancomycin. YhdP is a member of the AsmA-like family of proteins, sharing a common AsmA-like domain, and so may share similar functions. The project will investigate YhdP and the other AsmA-like proteins, namely AsmA, TamB, YhjG, YicH and YdbH, to determine their role in outer membrane biogenesis in gram-negative bacteria. A multidisciplinary approach involving biochemistry, biophysics and molecular biology techniques will be used, including X-ray crystallography, neutron reflectometry and cryo-electron microscopy. This project will contribute to our existing knowledge of this enigmatic process and may lead to the discovery of novel antibiotic targets to combat the public health threat of rising antimicrobial resistance.