Phage-Defense Systems Are Unlikely to Cause Cell Suicide

As new phage-defense systems (PDs) are discovered, the overlap between their mechanisms and those of toxin/antitoxin systems (TAs) is becoming clear in that both use similar means to reduce cellular metabolism; for example, both systems have members that deplete energetic compounds (e.g., NAD(+), ATP) and deplete nucleic acids, and both have members that inflict membrane damage. Moreover, both TAs and PDs are similar in that rather than altruistically killing the host to limit phage propagation (commonly known as abortive infection), both reduce host metabolism since phages propagate less in slow-growing cells, and slow growth facilitates the interaction of multiple phage-defense systems.

Automated summary

The overlap between phage-defense systems (PDs) and toxin/antitoxin systems (TAs) has become clear as new PDs are discovered, as both systems use similar means to reduce cellular metabolism. They both have members that deplete energetic compounds and nucleic acids, and inflict membrane damage. Additionally, both systems reduce host metabolism to limit phage propagation and interaction of multiple defense systems.