RNA Polymerase Backtracking in Gene Regulation and Genome Instability

RNA Polymerase Backtracking in Gene Regulation and Genome Instability

RNA polymerase is a ratchet machine that oscillates between productive and backtracked states at numerous DNA positions. Since its first description 15 years ago, backtracking--the reversible sliding of RNA polymerase along DNA and RNA--has been implicated in many critical processes in bacteria and eukaryotes, including the control of transcription elongation, pausing, termination, fidelity, an...

Linking RNA Polymerase Backtracking to Genome Instability in E. coli

Frequent codirectional collisions between the replisome and RNA polymerase (RNAP) are inevitable because the rate of replication is much faster than that of transcription. Here we show that, in E. coli, the outcome of such collisions depends on the productive state of transcription elongation complexes (ECs). Codirectional collisions with backtracked (arrested) ECs lead to DNA double-strand bre...

RNA Polymerase II Phosphorylation and Gene Expression Regulation

Backtracking by RNA polymerase: single molecule experiments vs theory

RNA polymerase II (RNAP II) is responsible for transcribing all mRNAs in eukaryotic cells in a highly regulated process that is conserved from yeast to human and that serves as a central control point for cellular function. We have investigated the transcription dynamics of single RNAP II molecules against force in a single-molecule dual-trap optical-tweezers assay. Remarkably , we found that t...

Ubiquitous Transcriptional Pausing Is Independent of RNA Polymerase Backtracking

RNA polymerase (RNAP) transcribes DNA discontinuously, with periods of rapid nucleotide addition punctuated by frequent pauses. We investigated the mechanism of transcription by measuring the effect of both hindering and assisting forces on the translocation of single Escherichia coli transcription elongation complexes, using an optical trapping apparatus that allows for the detection of pauses...