Staphylococcus aureus Survives with a Minimal Peptidoglycan Synthesis Machine but Sacrifices Virulence and Antibiotic Resistance.
Staphylococcus aureus Survives with a Minimal Peptidoglycan Synthesis Machine but Sacrifices Virulence and Antibiotic Resistance.
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DOI：
10.1371/journal.ppat.1004891
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发表时间：
2015-05
期刊：
影响因子：
6.7
通讯作者：
Pinho MG
中科院分区：
文献类型：
--
作者：
Reed P;Atilano ML;Alves R;Hoiczyk E;Sher X;Reichmann NT;Pereira PM;Roemer T;Filipe SR;Pereira-Leal JB;Ligoxygakis P;Pinho MG
许多重要的细胞过程是由分子机器执行的，分子机器由多个蛋白质组成，这些蛋白质相互作用以执行生物功能。细菌肽聚糖(PG)合成机就是一个例子，它负责合成细胞壁的主要成分，也是许多当代抗生素的靶标。确定细胞机器的基本组件的一种方法涉及确定其最小蛋白质组成。金黄色葡萄球菌是一种革兰氏阳性病原体，以其对多种常用抗生素的耐药性和在医院的流行而闻名。与其他模式生物相比，其基因组编码的具有PG合成活性的蛋白质数量较少(9种蛋白质)，因此是研究最小PG合成机器的良好模型。我们从金黄色葡萄球菌基因组中删除了9个编码PG合成酶的基因中的7个，在不影响正常生长或细胞形态的情况下，产生了一株仅由两种青霉素结合蛋白PBP1和双功能PBP2催化合成PG的菌株。然而，在临床相关的环境中，多个PBPs是重要的，因为具有最少PG合成机制的细菌对针对细胞壁的抗生素和宿主裂解酶变得高度敏感，并且在依赖于特定肽聚糖受体蛋白(即PGRP-SA)存在的果蝇感染模型中显示出毒力受损。金黄色葡萄球菌只有两个活性的PG合成酶才能生长和分裂的事实表明，大多数这些酶在体外都是多余的，并确定了金黄色葡萄球菌最小的PG合成机制。然而，除了体外生长外，复杂的分子机器在环境中也很重要，因为可消耗的PG合成酶在金黄色葡萄球菌的致病性和耐药性中起着重要作用。肽聚糖形成承受压力的球囊，防止细菌因膨胀压力而溶解。因此，肽聚糖的完整性对细菌的生存至关重要，它的合成是许多重要抗生素的靶标，如青霉素。肽聚糖合成的最后一步是由青霉素结合蛋白催化的，青霉素结合蛋白是一种被认为在多酶复合体中工作的酶。我们发现，编码肽聚糖合成酶的9个基因中的7个可以从金黄色葡萄球菌基因组中删除，而不会影响体外正常的生长和细胞形态，从而确定了这种生物最小的肽聚糖合成机制。最小机器的识别是合成生物学努力以降低复杂性的系统设计的关键。然而，非必需的肽聚糖合成蛋白对于金黄色葡萄球菌在更具挑战性的环境中的生存是重要的，例如在靶向细胞壁合成的抗生素存在的情况下或在宿主内，正如突变株无法建立成功的感染和杀死果蝇所表明的那样。
Many important cellular processes are performed by molecular machines, composed of multiple proteins that physically interact to execute biological functions. An example is the bacterial peptidoglycan (PG) synthesis machine, responsible for the synthesis of the main component of the cell wall and the target of many contemporary antibiotics. One approach for the identification of essential components of a cellular machine involves the determination of its minimal protein composition. Staphylococcus aureus is a Gram-positive pathogen, renowned for its resistance to many commonly used antibiotics and prevalence in hospitals. Its genome encodes a low number of proteins with PG synthesis activity (9 proteins), when compared to other model organisms, and is therefore a good model for the study of a minimal PG synthesis machine. We deleted seven of the nine genes encoding PG synthesis enzymes from the S. aureus genome without affecting normal growth or cell morphology, generating a strain capable of PG biosynthesis catalyzed only by two penicillin-binding proteins, PBP1 and the bi-functional PBP2. However, multiple PBPs are important in clinically relevant environments, as bacteria with a minimal PG synthesis machinery became highly susceptible to cell wall-targeting antibiotics, host lytic enzymes and displayed impaired virulence in a Drosophila infection model which is dependent on the presence of specific peptidoglycan receptor proteins, namely PGRP-SA. The fact that S. aureus can grow and divide with only two active PG synthesizing enzymes shows that most of these enzymes are redundant in vitro and identifies the minimal PG synthesis machinery of S. aureus. However a complex molecular machine is important in environments other than in vitro growth as the expendable PG synthesis enzymes play an important role in the pathogenicity and antibiotic resistance of S. aureus. Peptidoglycan forms the stress-bearing sacculus that prevents lysis of bacteria due to turgor pressure. The integrity of peptidoglycan is therefore essential for bacterial survival and its synthesis is the target of many important antibiotics, such as penicillin. The final steps of peptidoglycan synthesis are catalyzed by penicillin-binding proteins, enzymes that are proposed to work in multi-enzyme complexes. We show that seven of the nine genes encoding peptidoglycan synthesis enzymes can be deleted from the Staphylococcus aureus genome without affecting normal growth and cell morphology in vitro, identifying the minimal peptidoglycan synthesis machinery of this organism. Identification of minimal machineries is key for synthetic biology efforts towards the design of systems with reduced complexity. However, the non-essential peptidoglycan synthetic proteins are important for survival of S. aureus in more challenging environments, such as in the presence of antibiotics that target cell wall synthesis or within the host, as shown by the inability of the mutant strain to establish a successful infection and kill Drosophila flies.
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影响因子：
3.6
作者：
El Ghachi, Meriem;Matteie, Pierre-Jean;Boneca, Ivo G.
通讯作者：
Boneca, Ivo G.
DOI：
10.1073/pnas.1004304107
发表时间：
2010-11-02
影响因子：
11.1
作者：
Atilano, Magda L.;Pereira, Pedro M.;Filipe, Sergio R.
通讯作者：
Filipe, Sergio R.
影响因子：
3.7
作者：
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通讯作者：
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影响因子：
14.9
作者：
Boneca, IG;de Reuse, H;Moszer, I
通讯作者：
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影响因子：
3.2
作者：
Bera, Agnieszka;Biswas, Raja;Goetz, Friedrich
通讯作者：
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