Pentapeptide-rich peptidoglycan at the Bacillus subtilis cell-division site
Pentapeptide-rich peptidoglycan at the Bacillus subtilis cell-division site
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DOI：
10.1111/mmi.13629
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发表时间：
2017-04-01
影响因子：
3.6
通讯作者：
Scheffers, Dirk-Jan
中科院分区：
文献类型：
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作者：
Angeles, Danae Morales;Liu, Yun;Scheffers, Dirk-Jan
肽聚糖（PG）是细菌细胞壁的主要成分，是一种大分子。为了允许在细胞极点和分裂位点PG的不同曲率，PG的结构和最终的化学性质必须存在局部差异。在这里，我们报告这种革兰氏阳性杆状模式生物枯草芽孢杆菌的局部差异。抗生素处理后的单细胞分析和用荧光万古霉素类似物或荧光d -氨基酸类似物（FDAA） hcc -氨基- d -丙氨酸标记细胞壁显示，间隔处的PG含有含有未加工的茎肽（五肽）的多肽。虽然这些五肽在与PG结合后通常被缩短，但这种活性在分裂位点降低，表明PG交联的局部程度较低或PG组成的差异，这可能是其他蛋白质的拓扑标记。五肽在分裂后形成细胞的新极时，仍有部分未加工。未加工PG在分裂部位的积累不是由细胞分裂特异性青霉素结合蛋白2B的活性引起的。据我们所知，这是革兰氏阳性细菌中PG化学成分局部差异的第一个指示。
Peptidoglycan (PG), the major component of the bacterial cell wall, is one large macromolecule. To allow for the different curvatures of PG at cell poles and division sites, there must be local differences in PG architecture and eventually also chemistry. Here we report such local differences in the Gram-positive rod-shaped model organism Bacillus subtilis. Single-cell analysis after antibiotic treatment and labeling of the cell wall with a fluorescent analogue of vancomycin or the fluorescent D-amino acid analogue (FDAA) HCC-amino-D-alanine revealed that PG at the septum contains muropeptides with unprocessed stem peptides (pentapeptides). Whereas these pentapeptides are normally shortened after incorporation into PG, this activity is reduced at division sites indicating either a lower local degree of PG crosslinking or a difference in PG composition, which could be a topological marker for other proteins. The pentapeptides remain partially unprocessed after division when they form the new pole of a cell. The accumulation of unprocessed PG at the division site is not caused by the activity of the cell division specific penicillin-binding protein 2B. To our knowledge, this is the first indication of local differences in the chemical composition of PG in Gram-positive bacteria.