Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology in Warsaw, Warsaw, Poland.
Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu, Madrid, Spain.
Wiley Interdiscip Rev RNA. 2018 Nov;9(6):e1500. doi: 10.1002/wrna.1500. Epub 2018 Aug 3.
Bacterial plasmids constitute a wealth of shared DNA amounting to about 20% of the total prokaryotic pangenome. Plasmids replicate autonomously and control their replication by maintaining a fairly constant number of copies within a given host. Plasmids should acquire a good fitness to their hosts so that they do not constitute a genetic load. Here we review some basic concepts in plasmid biology, pertaining to the control of replication and distribution of plasmid copies among daughter cells. A particular class of plasmids is constituted by those that replicate by the rolling circle mode (rolling circle-replicating [RCR]-plasmids). They are small double-stranded DNA molecules, with a rather high number of copies in the original host. RCR-plasmids control their replication by means of a small short-lived antisense RNA, alone or in combination with a plasmid-encoded transcriptional repressor protein. Two plasmid prototypes have been studied in depth, namely the staphylococcal plasmid pT181 and the streptococcal plasmid pMV158, each corresponding to the two types of replication control circuits, respectively. We further discuss possible applications of the plasmid-encoded antisense RNAs and address some future directions that, in our opinion, should be pursued in the study of these small molecules. This article is categorized under: Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs RNA Structure and Dynamics > Influence of RNA Structure in Biological Systems.
细菌质粒构成了丰富的共享 DNA，约占原核泛基因组的 20%。质粒可以自主复制，并通过在给定的宿主中维持相当恒定的拷贝数来控制其复制。质粒应该与宿主有很好的适应性，以便它们不会构成遗传负担。在这里，我们回顾了一些质粒生物学的基本概念，涉及复制的控制和质粒拷贝在子细胞中的分配。一类特殊的质粒由通过滚环模式（滚环复制 [RCR]-质粒）复制的质粒构成。它们是小的双链 DNA 分子，在原始宿主中有相当高的拷贝数。RCR 质粒通过小的短寿命反义 RNA 单独或与质粒编码的转录阻遏蛋白结合来控制其复制。已经深入研究了两种质粒原型，即葡萄球菌质粒 pT181 和链球菌质粒 pMV158，它们分别对应于两种复制控制回路类型。我们进一步讨论了质粒编码的反义 RNA 的可能应用，并探讨了一些未来的方向，在我们看来，这些小分子的研究应该朝着这些方向发展。本文属于以下类别：调控 RNA/RNAi/核糖开关 > 调控 RNA 的结构和动态 > RNA 结构对生物系统的影响。
