Nutrient-dependent structural changes in S. aureus peptidoglycan revealed by solid-state NMR spectroscopy.
Nutrient-dependent structural changes in S. aureus peptidoglycan revealed by solid-state NMR spectroscopy.
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DOI：
10.1021/bi3012115
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发表时间：
2012-10-16
期刊：
影响因子：
2.9
通讯作者：
Cegelski L
中科院分区：
文献类型：
--
作者：
Zhou X;Cegelski L
细菌细胞壁对于细胞生存至关重要，也是抗生素的主要目标。细菌细胞壁的主要成分是肽聚糖，一种笼状大分子，可以保持细胞完整性并维持细胞形状。肽聚糖的不溶性和异质性对传统的结构分析提出了挑战。在这里，我们使用固态核磁共振结合特定同位素标记来定量、无损地探测金黄色葡萄球菌肽聚糖的关键结构特征。我们观察到细胞壁形态和肽聚糖结构都是金黄色葡萄球菌合成培养基（SASM）中生长阶段的函数。具体而言，与指数生长期的细胞相比，稳定期的金黄色葡萄球菌细胞具有更厚的细胞壁和不均匀增厚的隔膜，并且值得注意的是，其肽聚糖中 12% (±2%) 的茎没有附着五甘氨酸桥。从机制上讲，我们确定这些观察结果是由营养培养基中甘氨酸的耗尽引发的，这与稳定期的开始同时发生，并且可以通过添加过量的甘氨酸来防止结构改变的肽聚糖的产生。我们还证明，结构变化主要发生在新合成的肽聚糖中，而不是通过对先前合成的肽聚糖的修饰。总的来说，我们的观察强调了细菌细胞壁组装的可塑性以及通过外部刺激操纵肽聚糖结构的可能性。
The bacterial cell wall is essential to cell survival and is a major target of antibiotics. The main component of the bacterial cell wall is peptidoglycan, a cage-like macromolecule that preserves cellular integrity and maintains cell shape. The insolubility and heterogeneity of peptidoglycan pose a challenge to conventional structural analyses. Here we use solid-state NMR combined with specific isotopic labeling to probe a key structural feature of the Staphylococcus aureus peptidoglycan quantitatively and nondestructively. We observed that both the cell-wall morphology and the peptidoglycan structure are functions of growth stage in S. aureus synthetic medium (SASM). Specifically, S. aureus cells at stationary phase have thicker cell walls with non-uniformly thickened septa compared to cells in exponential phase and, remarkably, 12% (±2%) of the stems in their peptidoglycan do not have pentaglycine bridges attached. Mechanistically, we determined that these observations are triggered by the depletion of glycine in the nutrient medium, which is coincident with the start of the stationary phase, and that the production of the structurally altered peptidoglycan can be prevented by the addition of excess glycine. We also demonstrated that the structural changes primarily arise within newly synthesized peptidoglycan rather than through the modification of previously synthesized peptidoglycan. Collectively, our observations emphasize the plasticity in bacterial cell-wall assembly and the possibility to manipulate peptidoglycan structure with external stimuli.
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影响因子：
5.2
作者：
Mercier, RC;Stumpo, C;Rybak, MJ
通讯作者：
Rybak, MJ
影响因子：
2.9
作者：
Cegelski, L;Kim, SJ;Schaefer, J
通讯作者：
Schaefer, J
影响因子：
4.8
作者：
Frankel, Matthew B.;Hendrickx, Antoni P. A.;Schneewind, Olaf
通讯作者：
Schneewind, Olaf
DOI：
10.1073/pnas.0510182103
发表时间：
2006-03-21
影响因子：
11.1
作者：
Meroueh, SO;Bencze, KZ;Mobashery, S
通讯作者：
Mobashery, S
影响因子：
15
作者：
Kern, Thomas;Giffard, Mathilde;Simorre, Jean-Pierre
通讯作者：
Simorre, Jean-Pierre