Transcriptional Dynamics in Bacterial RNA Polymerase

Bacterial RNA polymerase (RNAP) orchestrates the conversion of genetic information into RNA through a finely tuned cycle of initiation, elongation, pausing, proofreading and termination. During elongation, RNAP advances along the DNA template in discrete nucleotide-addition steps. Intrinsic sequence elements and nascent RNA structures can induce transient pauses, which regulate the timing of transcript folding, recruitment of processing factors and synchronisation with downstream processes. Pausing also enables RNAP to backtrack when misincorporation occurs, allowing auxiliary factors to stimulate cleavage of the aberrant RNA segment and restore productive elongation. Transcription–translation coupling, a hallmark of prokaryotic gene expression, mechanically links the ribosome to the trailing polymerase, thereby accelerating elongation and reducing deleterious pauses. Termination is achieved either by intrinsic hairpin formation in the nascent RNA or via the Rho factor, which binds emerging transcripts and engages paused RNAP to trigger release of RNA and dissociation of the elongation complex. Regulatory proteins such as NusA and NusG further modulate pause duration, pausing frequency and backtracking propensity, integrating environmental signals into dynamic control of gene expression. Insights into the structural basis of RNAP conformational changes, the force-dependent interplay with ribosomes and the routes to Rho-dependent termination are reshaping our understanding of bacterial transcription as a mechanically and chemically coordinated process with broad implications for antibiotic targeting and synthetic biology applications.

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Transcriptional Dynamics in Bacterial RNA Polymerase publication trend

The graph below shows the total number of articles in transcriptional dynamics in bacterial rna polymerase across all publications each year (not limited to Nature Index journals).

Technical terms

Transcription elongation: The process by which RNAP synthesises RNA by successive addition of ribonucleotides to the 3′ end of the growing transcript.

Pausing: A transient halt in RNA chain extension induced by sequence motifs or nascent RNA structures that allows regulatory interactions and error correction.

Backtracking: A reverse translocation of RNAP along the DNA that extrudes the RNA 3′ end into the enzyme’s secondary channel, facilitating proofreading.

Transcription–translation coupling: The physical and functional linkage of RNAP and ribosome that synchronises RNA synthesis with protein synthesis in bacteria.

Rho-dependent termination: A termination mechanism in which the Rho factor binds nascent RNA, translocates along it and disengages the transcript and polymerase from the DNA template.

NusA/NusG: Conserved transcription factors in bacteria: NusA stabilises paused complexes and RNA hairpins, while NusG modulates pause frequencies and suppresses backtracking.

References

1. A trailing ribosome speeds up RNA polymerase at the expense of transcript fidelity via force and allostery. Cell (2023).
2. Transcriptional pause extension benefits the stand-by rather than catch-up Rho-dependent termination. Nucleic Acids Research (2023).
3. Structural Basis for NusA Stabilized Transcriptional Pausing. Molecular Cell (2018).
4. Structure of RNA polymerase bound to ribosomal 30S subunit. eLife (2017).
5. NusG inhibits RNA polymerase backtracking by stabilizing the minimal transcription bubble. eLife (2016).