Mechanisms of plasmid segregation: have multicopy plasmids been overlooked?
Mechanisms of plasmid segregation: have multicopy plasmids been overlooked?
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DOI：
10.1016/j.plasmid.2014.07.002
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发表时间：
2014-09
期刊：
影响因子：
2.6
通讯作者：
Camps M
中科院分区：
文献类型：
--
作者：
Million-Weaver S;Camps M
质粒是可以自我复制的DNA片段，可以帮助非必需基因的传播。鉴于质粒代表宿主的代谢负担，确保质粒传递到子细胞的机制对于它们在群体中的稳定维持至关重要。在这里，我们回顾这些机制，集中在两个积极的分区策略常见的低拷贝质粒：PAR系统I型和II型。两者都涉及三个组成部分：衔接蛋白、马达蛋白和着丝粒，所述着丝粒是质粒中被衔接蛋白识别的序列区域。着丝粒结合的适配器使马达的聚合成核，导致细丝形成，这可以将质粒拉开（第一部分）或将它们推向细胞的相反两极（第二部分）。已知在高拷贝数质粒中不存在这样的主动分配机制。在这种情况下，垂直传播通常被认为是随机的，因为质粒在细胞质中的随机分布。我们讨论的概念和实验线的证据质疑的随机分布模型和隔离机制的存在，在高拷贝数质粒移动质粒到细胞极点，以促进传输到子细胞。这种机制将涉及染色体编码的蛋白质和质粒复制起点。调节这种分离机制可以提供新的方法来提高重组基因表达背景下的质粒稳定性，这限制了大规模蛋白质生产和生物修复。
Plasmids are self-replicating pieces of DNA that can help dissemination of non-essential genes. Given that plasmids represent a metabolic burden to the host, mechanisms ensuring plasmid transmission to daughter cells are critical for their stable maintenance in the population. Here we review these mechanisms, focusing on two active partition strategies common to low-copy plasmids: par systems type I and II. Both involve three components: an adaptor protein, a motor protein, and a centromere, which is a sequence area in the plasmid that is recognized by the adaptor protein. The centromere-bound adaptor nucleates polymerization of the motor, leading to filament formation, which can pull plasmids apart (par I) or push them towards opposite poles of the cell (par II). No such active partition mechanisms are known to occur in high copy number plasmids. In this case, vertical transmission is generally considered stochastic, due to the random distribution of plasmids in the cytoplasm. We discuss conceptual and experimental lines of evidence questioning the random distribution model and posit the existence of a mechanism for segregation in high copy number plasmids that moves plasmids to cell poles to facilitate transmission to daughter cells. This mechanism would involve chromosomally-encoded proteins and the plasmid origin of replication. Modulation of this proposed mechanism of segregation could provide new ways to enhance plasmid stability in the context of recombinant gene expression, which is limiting for large-scale protein production and for bioremediation.
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影响因子：
5.6
作者：
BERNARD, P;KEZDY, KE;COUTURIER, M
通讯作者：
COUTURIER, M
影响因子：
7.8
作者：
Campbell, Christopher S.;Mullins, R. Dyche
通讯作者：
Mullins, R. Dyche
影响因子：
4.5
作者：
Ah-Seng, Yoan;Rech, Jerome;Bouet, Jean-Yves
通讯作者：
Bouet, Jean-Yves
影响因子：
11.4
作者：
Barillá, D;Rosenberg, MF;Hayes, F
通讯作者：
Hayes, F
影响因子：
56.9
作者：
Garner, Ethan C.;Campbell, Christopher S.;Mullins, R. Dyche
通讯作者：
Mullins, R. Dyche