Amidase activity is essential for medial localization of AmiC in Caulobacter crescentus
Amidase activity is essential for medial localization of AmiC in Caulobacter crescentus
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DOI：
10.1007/s00294-017-0781-9
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发表时间：
2018-06-01
期刊：
影响因子：
2.5
通讯作者：
Priyadarshini, Richa
中科院分区：
文献类型：
--
作者：
Dubey, Amrita;Priyadarshini, Richa
细菌细胞分裂是一个复杂的过程，由多种蛋白质的协调作用所带来。在分裂的最后阶段，子细胞的分离包括在分裂隔膜处新细胞壁的分裂。在大肠在大肠杆菌中，该过程由N-乙酰胞壁酰-L-丙氨酸酰胺酶AmiA/B/C的作用控制，AmiA/B/C受其LytM激活剂EnvC和NlpD的调节。虽然对E. coli中分离子细胞的机制尚不清楚，新月柄杆菌（Caulobacter crescentus）是一种二型新月形细菌。在这项工作中，我们的特点的作用AmiC，唯一注释的酰胺酶在C。crescentus。AmiC来自C. crescentus在E.并恢复了在大肠杆菌中观察到的细胞分离缺陷。coli酰胺酶突变体，表明AmiC具有隔膜裂解活性。AmiC的内侧定位独立于DipM，一种含有LytM结构域的内肽酶。我们的研究结果表明，酶活性是必不可少的中间募集的AmiC。AmiC的过表达导致细胞分离缺陷和链的形成。最后，AmiC在细胞分裂受抑制的细胞中的过表达导致裂解。总的来说，我们的研究结果表明，在C。crescentus与E.该系统可作为研究细菌胞质分裂的模型系统。
Bacterial cell division is a complex process brought about by the coordinated action of multiple proteins. Separation of daughter cells during the final stages of division involves cleavage of new cell wall laid down at the division septum. In E. coli, this process is governed by the action of N-acetylmuramoyl-L-alanine amidases AmiA/B/C, which are regulated by their LytM activators EnvC and NlpD. While much is known about the regulation of septum cleavage in E. coli, the mechanism of daughter cell separation is not clear in Caulobacter crescentus, a dimorphic crescent-shaped bacterium. In this work, we characterized the role of AmiC, the only annotated amidase in C. crescentus. AmiC from C. crescentus is functional in E. coli and restores cell separation defects seen in E. coli amidase mutants, suggesting that AmiC has septum splitting activity. The medial localization of AmiC was independent of DipM, an LytM domain-containing endopeptidase. Our results indicate that enzymatic activity is essential for medial recruitment of AmiC. Overexpression of AmiC causes cell separation defects and formation of chains. Finally, overexpression of AmiC in cells inhibited for cell division leads to lysis. Collectively, our findings reveal that regulation of daughter cell separation in C. crescentus differs from that of E. coli and can serve as a model system to study bacterial cytokinesis.