Widespread prevalence of a methylation-dependent switch to activate an essential DNA damage response in bacteria

DNA methylation plays central roles in diverse cellular processes, ranging from error-correction during replication to regulation of bacterial defense mechanisms. Nevertheless, certain aberrant methylation modifications can have lethal consequences. The mechanisms by which bacteria detect and respond to such damage remain incompletely understood. Here, we discover a highly conserved but previously uncharacterized transcription factor (Cada2), which orchestrates a methylation-dependent adaptive response in Caulobacter. This response operates independently of the SOS response, governs the expression of genes crucial for direct repair, and is essential for surviving methylation-induced damage. Our molecular investigation of Cada2 reveals a cysteine methylation-dependent posttranslational modification (PTM) and mode of action distinct from its Escherichia coli counterpart, a trait conserved across all bacteria harboring a Cada2-like homolog instead. Extending across the bacterial kingdom, our findings support the notion of divergence and coevolution of adaptive response transcription factors and their corresponding sequence-specific DNA motifs. Despite this diversity, the ubiquitous prevalence of adaptive response regulators underscores the significance of a transcriptional switch, mediated by methylation PTM, in driving a specific and essential bacterial DNA damage response.

A new Achilles heel of the bacterial cell wall

The bacterial cell wall must be constantly remodeled in order to grow and divide. This involves the close coordination of lytic enzymes and peptidoglycan synthesis. In their study published in Nature Communications, researchers led by Martin Thanbichler have now found that a central regulator can control completely different classes of autolysins. Since many antibiotics target the bacterial cell wall, these findings may contribute to the development of new therapeutic strategies against bacterial infections.

Phase Separation of Scaffold Protein Regulates Microbial Asymmetric Cell Division

eDNA-stimulated cell dispersion from Caulobacter crescentus biofilms upon oxygen limitation is dependent on a toxin-antitoxin system

Prophage-like gene transfer agents promote Caulobacter crescentus survival and DNA repair during stationary phase

The model organism Caulobacter crescentus is found to produce a prophage-like gene transfer agent that mediates survival to stationary phase and DNA damaging conditions by providing genomic DNA from donor cells for recombination-based repair in recipient cells.