Fast lysis of Escherichia coli filament cells requires differentiation of potential division sites
Fast lysis of Escherichia coli filament cells requires differentiation of potential division sites
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DOI：
10.1099/00221287-148-1-79
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发表时间：
2002-01-01
期刊：
影响因子：
2.8
通讯作者：
Schwarz, H
中科院分区：
文献类型：
--
作者：
de Pedro, MA;Höltje, JV;Schwarz, H
最近报道了大肠杆菌分裂时带状肽聚糖（胞壁素）合成的周期性激活。带状合成是为了形成隔膜，而细胞球囊的伸长是由前体的扩散插入进行的。带状合成可以触发ftsA，和ftsI（pbpB）分裂突变体生长的限制性温度下的细丝，但不是在ftsZ突变株。能够或不能周期性触发胞壁素的带状模式的β-内酰胺类细胞的裂解反应可能是实质性不同的。因此，我们研究了在限制性温度（42 ℃）下生长的ftsZ和ftsI突变体对溶菌β-内酰胺头孢磺啶的反应。在加入抗生素后，ftsI细胞早期和快速裂解。以锋利的方式横向切割裂解细胞的球囊。相比之下，ftsI菌株在添加抗生素后裂解较晚且缓慢，并且球囊显示出胞壁蛋白的普遍弱化和具有磨损外观的延长断裂。我们的研究结果支持β-内酰胺诱导的裂解优先发生在分裂位点，因为在分隔开始时激活了带状胞壁蛋白的合成。
Periodic activation of zonal peptidoglycan (murein) synthesis at division in Escherichia coli has been reported recently. Zonal synthesis is for septum formation, whereas elongation of the cell sacculus is performed diffuse insertion of precursors. Zonal synthesis can be triggered in ftsA, and ftsI (pbpB) division mutants growing as filaments at the restrictive temperature, but not in ftsZ mutant strains. The lytic response to beta-lactams cells able or unable to periodically trigger a zonal mode of murein could be substantially different. Therefore, we investigated the response to the bacteriolytic beta-lactam cefsulodin of ftsZ and ftsI mutants growing at restrictive (42 degreesC) temperature. The ftsI cells lysed early and quickly after addition of the antibiotic. Sacculi of lysed cells were transversely cut in a sharp way. In contrast the ftsI strain lysed late and slowly after addition of antibiotic and sacculi showed a generalized weakening of the murein and extended breaks with a frayed appearance. No transversely cut sacculi comparable to those seen in the ftsl samples were found. Our results support that beta-lactam-induced lysis occurs preferentially at division sites because of the activation of zonal murein synthesis at the initiation of septation.