Investigated
What phage proteases target bacterial sensors?
Short answer
Image: pmc.ncbi.nlm.nih.gov
The clearest identified targets are CBASS CD-NTase immune sensors: phage prohead proteases cut a surface-exposed activation loop, switching nucleotide-signal production on during infection. This appears to be a broader strategy rather than a complete list: diverse CBASS systems can sense protease activity, while other phage proteins trigger or suppress bacterial nucleotide defenses through additional mechanisms.
The views on this question
Two lenses on the same evidence. Source weight and the primary source ratio show what each rests on.
Broader Picture
Source weight 56%Lens adapted to this topic: Other triggers and competing mechanisms
A broader reading treats prohead-protease sensing as one part of a larger arms race. Phages can also manipulate bacterial nucleotide immunity by degrading or sequestering signaling molecules, and systematic phage-protein screens identify multiple kinds of immune triggers. This does not overturn the prohead-protease result; it cautions against treating it as the only way phages target bacterial sensors or defenses.
- Phage counterdefenses include nucleases and other proteins that directly degrade cyclic nucleotide signals rather than cleaving bacterial sensors.
- Phage proteins can trigger known and previously undiscovered bacterial antiphage systems, suggesting additional sensor-targeting mechanisms remain to be mapped.
- Reviews place CBASS alongside other nucleotide-signaling defenses, including Pycsar, Thoeris, and CRISPR-associated pathways.
- The evidence supports prohead proteases as a major identified trigger, but not as an exhaustive explanation for phage detection.