Tertiary structure of bacterial murein: The scaffold model
Tertiary structure of bacterial murein: The scaffold model
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DOI：
10.1128/jb.185.11.3458-3468.2003
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发表时间：
2003-06-01
影响因子：
3.2
通讯作者：
Ehlers, S
中科院分区：
文献类型：
--
作者：
Dmitriev, BA;Toukach, FV;Ehlers, S
尽管肽聚糖的化学结构和物理性质已经阐明了一段时间，但胞壁蛋白的精确三维结构仍然难以捉摸。早期发表的细菌胞壁蛋白结构的计算机模拟了肽聚糖链的规则（D。Pink，J. Moeller，B. Quinn，M. Jericho和T. Beveridge，J. Bacteriol. 182：5925-5930，2000）或不规则的（A. Koch，J. Theor. 204：533-541，2000）相对于质膜平行取向。然而，在将已发表的关于聚糖链长度分布和肽侧链交联程度的实验数据整合到该计算机模拟中之后，我们现在报告所提出的胞壁蛋白平面网络似乎在很大程度上功能失调。相比之下，一个支架模型的murein架构，它假设聚糖链延伸垂直于质膜，被发现，以适应已发表的实验证据，并产生一个可行的应力承载矩阵。此外，该模型符合胞壁蛋白在体内组装的公认原理，即，链与预先存在的结构的顺序连接。这是第一次，分裂细菌中分裂平面交替的现象可以与胞壁蛋白分子结构的计算机模型相协调。
Although the chemical structure and physical properties of peptidoglycan have been elucidated for some time, the precise three-dimensional organization of murein has remained elusive. Earlier published computer simulations of the bacterial murein architecture modeled peptidoglycan strands in either a regular (D. Pink, J. Moeller, B. Quinn, M. Jericho, and T. Beveridge, J. Bacteriol. 182: 5925-5930, 2000) or an irregular (A. Koch, J. Theor. Biol. 204: 533-541, 2000) parallel orientation with respect to the plasma membrane. However, after integrating published experimental data on glycan chain length distribution and the degree of peptide side chain cross-linking into this computer simulation, we now report that the proposed planar network of murein appears largely dysfunctional. In contrast, a scaffold model of murein architecture, which assumes that glycan strands extend perpendicularly to the plasma membrane, was found to accommodate published experimental evidence and yield a viable stress-bearing matrix. Moreover, this model is in accordance with the well-established principle of murein assembly in vivo, i.e., sequential attachment of strands to the preexisting structure. For the first time, the phenomenon of division plane alternation in dividing bacteria can be reconciled with a computer model of the molecular architecture of murein.