Scientists identify hidden mechanism driving RNA synthesis targeted by antibiotics

Scientists have long studied two promising classes of antibiotics that disable bacterial RNA polymerase (RNAP), the enzyme that drives gene expression. By binding to specific sites within the polymerase, these drugs can halt transcription in a range of pathogens, including the bacterium that causes tuberculosis. However, despite decades of research, the precise cellular process that these antibiotics interrupt remained unclear.

Recent work has clarified the mechanism of action. Using high‑resolution structural analyses and biochemical assays, researchers showed that the drugs bind to the active‑center cleft of RNAP and prevent the transition from the initiation to the elongation phase of transcription. The compounds lock the enzyme in a pre‑elongation state, effectively blocking the synthesis of messenger RNA and thereby crippling bacterial protein production. This finding explains why the antibiotics are effective against a broad spectrum of bacteria and provides a clear target for future drug‑design efforts.

The discovery of the exact transcriptional step targeted by these antibiotics offers a new foundation for the development of next‑generation antimicrobials. By focusing on the initiation‑to‑elongation transition, scientists can now design more potent inhibitors that may overcome resistance mechanisms and expand the therapeutic arsenal against drug‑resistant bacterial infections.