A RecBCD-like enzyme regulates expression of bacterial defense operons in response to DNA damage

CerC, a RecBC-like peptidase-helicase-nuclease fusion in the Cerberus pathway, senses dsDNA ends after DNA damage or RecBCD inhibition and activates defense operon transcription via CerB cleavage.

• Why it matters: Bacteria need rapid transcriptional defense programs when DNA damage generates dsDNA ends, but how these ends are converted into operon-level immune regulation is unclear.
• What they did: The authors identify Cerberus as a three-protein pathway and show that CerC binds and unwinds free dsDNA ends, allosterically activating its HExxH metallopeptidase to cleave CerB and release CerA.
• The result: By linking RecBCD-like DNA end sensing to anti-sigma factor cleavage, Cerberus enables CerA to drive nearby defense/immune operon expression specifically during DNA damage or RecBCD inhibition.

AI summary of the abstract · may contain errors · not medical advice · read the paper.