A DnaA‐dependent riboswitch for transcription attenuation of the his operon

Abstract

Transcription attenuation in response to the availability of a specific amino acid is believed to be controlled by alternative configurations of RNA secondary structures that lead to the arrest of translation or the release of the arrested ribosome from the leader mRNA molecule. In this study, we first report a possible example of the DnaA-dependent riboswitch for transcription attenuation in Escherichia coli. We show that (i) DnaA regulates the transcription of the structural genes but not that of the leader hisL gene; (ii) DnaA might bind to rDnaA boxes present in the HisL-SL RNA, and subsequently attenuate the transcription of the operon; (iii) the HisL-SL RNA and rDnaA boxes are phylogenetically conserved and evolutionarily important; and (iv) the translating ribosome is required for deattenuation of the his operon, whereas tRNA His strengthens attenuation. This mechanism seems to be phylogenetically conserved in Gram-negative bacteria and evolutionarily important.

Read-through transcription of tRNA underlies the cell cycle-dependent dissociation of IHF from the DnaA-inactivating sequence datA

“…Another possible role of the datA DnaA box 2 could be as a riboswitch for transcription attenuation. A recent study suggested that DnaA binds to the specific RNA sequence rDnaA box and plays a regulatory role for transcription termination ( Yao et al, 2023 ).…”

Genome and transcriptomic analysis of the adaptation of Escherichia coli to environmental stresses

“…Huang et al reported that histone-like proteins, H-Ns and IHF, in E. coli affected the higher-order DNA compaction while H-NS and IHF regulated the gene expression as transcription factors. Similarly, the transcription factor DnaA has also been shown to affect the compaction of nucleoid [68] , [69] and RNA structures [70] . Le Berre et al observed the link between gene expression and chromosomal spatial organization, which turned out to be essential for bacterial adaptation to changing environmental circumstances [71] .…”

Editorial: Bacterial transcription factors and the cell cycle, volume II

“…As reviewed recently (Menikpurage et al, 2021 ), DnaA might be involved in the development of different cellular events of quorum sensing, cell motility, DNA repair (Wurihan et al, 2018 ), and cell cycle control by regulating the expression of the genes associated. Most recently, DnaA was reported to regulate transcription attenuation of the his operon (Yao et al, 2023 ). Other transcription factors, for example, RpoS in Coxiella controls the expression of the developmental cycle genes (Moormeier et al, 2019 ), and BolA in the Gram-negative bacteria turns on biofilm development while it turns off motility as a transcription factor (Dressaire et al, 2015 ).…”