Replication of plasmids in gram-negative bacteria.
Replication of plasmids in gram-negative bacteria.
复制标题
DOI：
10.1128/mmbr.53.4.491-516.1989
复制
发表时间：
1989-12
期刊：
影响因子：
--
通讯作者：
U. Kües;U. Stahl
中科院分区：
文献类型：
--
作者：
U. Kües;U. Stahl
质粒脱氧核糖核酸 (DNA) 的复制取决于三个阶段：起始、延伸和终止。第一阶段，即起始阶段，取决于质粒编码的特性，例如复制起点，以及在大多数情况下的复制起始蛋白（Rep 蛋白）。近年来，人们对大肠杆菌中质粒复制的启动和调控的认识有了显着提高，但只有 ColE1 型质粒存在有关 DNA 合成初始引发反应的重要生化数据。 ColE1 复制的启动和调节的详细模型已经开发出来。对于其他质粒，例如 pSC101，提出了一些启动机制和复制起始的假设。这些假设基于实验证据和与其他系统（例如大肠杆菌的染色体起源）的推测性比较。在大多数情况下，有关质粒复制的知识仅限于调控机制。这些机制协调质粒复制到宿主细胞周期，并且它们似乎还确定质粒的宿主范围。大多数研究的质粒表现出狭窄的宿主范围，仅限于大肠杆菌和相关细菌。相比之下，其他一些质粒，例如 IncP 质粒 RK2 和 IncQ 质粒 RSF1010，能够在几乎所有革兰氏阴性细菌中复制。这种广泛的宿主范围可能取决于必需的rep基因的正确表达，这可能是通过复杂的调节机制（RK2）或通过使用不同的启动子（RSF1010）介导的。或者或另外，由于其起源的结构和/或其复制起始蛋白的不同形式，宽宿主范围的质粒可以更好地适应参与起始的宿主酶。此外，当复制起始独立于宿主蛋白时，可以产生广泛的宿主范围，正如在 RSF1010 的引发反应中所发现的那样。
Replication of plasmid deoxyribonucleic acid (DNA) is dependent on three stages: initiation, elongation, and termination. The first stage, initiation, depends on plasmid-encoded properties such as the replication origin and, in most cases, the replication initiation protein (Rep protein). In recent years the understanding of initiation and regulation of plasmid replication in Escherichia coli has increased considerably, but it is only for the ColE1-type plasmids that significant biochemical data about the initial priming reaction of DNA synthesis exist. Detailed models have been developed for the initiation and regulation of ColE1 replication. For other plasmids, such as pSC101, some hypotheses for priming mechanisms and replication initiation are presented. These hypotheses are based on experimental evidence and speculative comparisons with other systems, e.g., the chromosomal origin of E. coli. In most cases, knowledge concerning plasmid replication is limited to regulation mechanisms. These mechanisms coordinate plasmid replication to the host cell cycle, and they also seem to determine the host range of a plasmid. Most plasmids studied exhibit a narrow host range, limited to E. coli and related bacteria. In contrast, some others, such as the IncP plasmid RK2 and the IncQ plasmid RSF1010, are able to replicate in nearly all gram-negative bacteria. This broad host range may depend on the correct expression of the essential rep genes, which may be mediated by a complex regulatory mechanism (RK2) or by the use of different promoters (RSF1010). Alternatively or additionally, owing to the structure of their origin and/or to different forms of their replication initiation proteins, broad-host-range plasmids may adapt better to the host enzymes that participate in initiation. Furthermore, a broad host range can result when replication initiation is independent of host proteins, as is found in the priming reaction of RSF1010.