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UvrD acts in nucleotide excision repair by using its helicase/translocase activity to induce RNA polymerase backtracking, enabling repair enzymes to access DNA lesions.

Here, using proteomics, next-generation sequencing, biochemistry and cryo-EM, the authors delineate the role of CedA as an unconventional transcription factor in Escherichia coli, which protects from different stressors, including antibiotics, by regulating the transcriptional landscape.

Here, using cryo-EM and biochemical methods, the authors demonstrate that second messenger (p)ppGpp regulates the bacterial RNA polymerase by binding to a site that is functionally relevant during transcriptional elongation but not initiation. Moreover, they demonstrate that binding to that site bears functional implications for nucleotide excision DNA repair and genome stability.

A collection of RNA polymerase mutants spanning all possible substitutions of the rifampicin binding site is generated and characterized, increasing our understanding of antibiotic mechanisms and bacterial physiology.

Computational, molecular and structural analyses reveal the presence of bacterial histones that bind DNA to form dense, DNA-enveloping fibres in Bdellovibrio bacteriovorus.

Transcription-Coupled DNA repair has been classically defined as the preferential repair of the template strand (TS) over the non-template strand (NTS). Here the authors challenge this classic model of TCR by using a genome-wide repair assay, CPD-seq, as well as RNA-seq, to show that TCR occurs across the entire E. coli genome – including NTS and intergenic regions.

Integrated structure–function studies show that transcription-coupled DNA repair (TCR)—rather than global genomic repair—is responsible for most chromosomal repair events in bacteria, and that TCR mainly occurs independently of the Mfd translocase.

A genome-wide Tn-seq analysis of the rpoB H526Y mutant, a rifampicin-resistant Escherichia coli strain, identifies non-essential genes that modulate the fitness cost of mutations in the bacterial RNA polymerase that confer antibiotic resistance.

Hydrogen sulfide (H2S) production in Escherichia coli is controlled by the sulfurtransferase 3MST. Here, the authors describe an alternative mechanism for H2S biosynthesis via activation of the thiosulfate sulfurtransferase PspE, a process mediated by the transcription factor YcjW.

Glycogen is a storage form of glucose in cells. Here, Gusarovet al. show that glycogen-derived glucose can be used to quickly regenerate the antioxidant glutathione and that inhibiting glycogen synthesis extends C. eleganslifespan, whereas glycogen accumulation drives organismal ageing in worms.

The exact mechanism by which cellular RNA polymerases translocate and maintain exceptionally high fidelity during transcription remains an important unresolved issue. Two recent structural studies of yeast RNA polymerase II in complex with its potent inhibitor, the fungal toxin α-amanitin, address this matter by describing crucial and surprising details about the dynamic organization of the enzyme catalytic center.

Direct time-resolved single-molecule observations of promoter search by Escherichia coli RNA polymerase indicate no evidence of facilitated diffusion, according to a new report.

Reactive oxygen species are required for the long lifespan, and glutathione is an antioxidant. Here the authors show that limiting the consumption of dietary thiols, including those naturally derived from the microbiota, increases proteotoxic stress resistance in worms and human cells, and extends C. elegans lifespan.

Maximum-depth sequencing (MDS), a new method of detecting extremely rare variants within a bacterial population, is used to show that mutation rates in Escherichia coli vary across the genome by at least an order of magnitude, and also to uncover mechanisms of antibiotic-induced mutagenesis.

Rho is a general transcription termination factor in bacteria, but the mechanism by which it disrupts the RNA polymerase (RNAP) elongation complex is unknown. Here, Rho is shown to bind tightly to the RNAP throughout the transcription cycle, with the formation of the RNAP–Rho complex being crucial for termination. Furthermore, RNAP is proposed to have an active role in Rho termination through an allosteric mechanism.