Fighting Antibiotic Resistant Tuberculosis: Structural Studies of an Mmpl

抗生素的广泛使用推动了许多病原菌耐药机制的演变，接近保证全球健康危机状态的水平。值得关注的是出现了多重、极端和完全耐药的结核分枝杆菌菌株--结核病的病原体，也是全世界与传染病相关的死亡的主要原因。由于对新型抗结核药物的发现不足，以及对在分子水平上实现耐药性的机制的了解不完全，这种情况进一步恶化。作为国际抗结核行动的一部分，这项总部位于牛津的隐秘计划正在利用10万株结核病分离株的全基因组测序，对已知和新的抗结核靶标的耐药性突变进行编目。该项目与CRYTIC合作，旨在使用结构生物学、功能生物化学和计算方法的组合来开始抗击耐抗生素结核病。最初的工作将集中在结核分枝杆菌膜蛋白的结构和功能特征上--以及与谷氨酸杆菌密切相关的同系物--在细胞壁生物合成(糖脂转运体MmpL3、CmpL1和CmpL3)或药物外排(MmpL5和NCgl-1194)中发挥作用。这两类蛋白都与抗结核耐药性有关，和/或是结核分枝杆菌生存所必需的；因此，这两种蛋白代表了新抗生素开发的假定靶点。应用类似的方法，以及在硅自由能计算中的互补，也将寻求对KatG(一种过氧化氢酶)的神秘突变如何能够促进对一线抗结核异烟肼(INH)的耐药性的机械理解。随着项目的进展，将进一步研究与耐药有关的新蛋白质。BBSRC优先领域：对抗抗菌素耐药性；BFH，ENWW

Widespread use of antibiotics has driven evolution of resistance mechanisms in many pathogenic bacteria, approaching levels that warrant global health crisis status. Of notable concern is the emergence of multi-, extremely and totally-drug resistant strains of M.tuberculosis-the aetiological agent of tuberculosis (TB) disease and the leading cause of infectious disease-associated mortality worldwide. The situation has been further compounded by insufficient discovery of novel antituberculars, as well as an incomplete understanding of the mechanisms by which resistance is achieved at the molecular level. Spearheading part of an international anti-TB response, the Oxford-based CRyPTIC initiative is using whole-genome sequencing of >100,000 TB isolates to catalogue resistance mutations in both known and novel antitubercular targets. In collaboration with CRyPTIC, this project aims to use a combination of structural biology, functional biochemistry and computational approaches to begin combatting antibiotic resistant TB. Initial efforts will focus on the structural and functional characterisation of M.tuberculosis membrane proteins-alongside closely related C.glutamicum homologues-functioning in cellwall biosynthesis (the glycolipid transporters MmpL3, CmpL1 & CmpL3) or drug-efflux (MmpL5 & NCgl-1194). Both classes of protein have been implicated in antitubercular resistance and/or are required for M.tuberculosisviability; thus representing putative targets against which new antibiotics could be developed. Applying similar methodology, alongside complementary in silico free-energy calculations, a mechanistic understanding of how CRyPTIC-identified mutations in KatG (a catalase-peroxidase) are able to promote resistance to the front-line antitubercular isoniazid (INH) will also be sought. As the project progresses, new proteins implicated in resistance by CRyPTIC will be additionally investigated.BBSRC Priority Area: Combatting Antimicrobial Resistance; BfH, ENWW