Читать книгу Structure and Function of the Bacterial Genome - Charles J. Dorman - Страница 43

The linking number of DNA is changed at a local level by the processes of transcription and DNA replication. In 1987, Liu and Wang proposed, in a landmark theoretical paper, that the process of transcription would induce overwinding of the DNA template ahead of RNA polymerase and underwinding behind (Liu and Wang 1987) (Figure 1.15). Experimental studies provided support for the proposal, leading to the realisation that topoisomerases play important roles in transcription by relieving the torsional stress that the process creates (Ahmed et al. 2017; Chong et al. 2014; Higgins 2014; Rahmouni and Wells 1992; Rani and Nagaraja 2019; Wu et al. 1988). The role of local DNA supercoiling in the modulation of transcription and in gene‐to‐gene communication will be addressed in Section 8.2. Here we will consider the impact of transcription on nucleoid architecture and on DNA replication.