Centre for Bacterial Cell Biology, Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle Upon Tyne, UK.
Mol Microbiol. 2023 Oct;120(4):539-546. doi: 10.1111/mmi.15076. Epub 2023 May 15.
The flow of genetic information from the chromosome to protein in all living organisms consists of two steps: (1) copying information coded in DNA into an mRNA intermediate via transcription by RNA polymerase, followed by (2) translation of this mRNA into a polypeptide by the ribosome. Unlike eukaryotes, where transcription and translation are separated by a nuclear envelope, in bacterial cells, these two processes occur within the same compartment. This means that a pioneering ribosome starts translation on nascent mRNA that is still being actively transcribed by RNA polymerase. This tethering via mRNA is referred to as 'coupling' of transcription and translation (CTT). CTT raises many questions regarding physical interactions and potential mutual regulation between these large (ribosome is ~2.5 MDa and RNA polymerase is 0.5 MDa) and powerful molecular machines. Accordingly, we will discuss some recently discovered structural and functional aspects of CTT.
（1）通过 RNA 聚合酶的转录，将 DNA 中编码的信息复制到 mRNA 中间产物中，然后（2）核糖体将此 mRNA 翻译成多肽。与转录和翻译被核膜隔开的真核生物不同，在细菌细胞中，这两个过程发生在同一个隔室中。这意味着一个开创性的核糖体在 RNA 聚合酶仍在积极转录的新生 mRNA 上开始翻译。这种通过 mRNA 的系留被称为转录和翻译的“偶联”（CTT）。CTT 提出了许多关于这些大型（核糖体约为 2.5MDa，RNA 聚合酶为 0.5MDa）和强大的分子机器之间物理相互作用和潜在相互调节的问题。因此，我们将讨论 CTT 的一些最近发现的结构和功能方面。
