Beyond AMGs: Phage-encoded transcription and sigma factors as understudied virocell reprogramming tools.

Phage-encoded host-acting transcription and sigma factors (TSFs) are prevalent in phages and may significantly influence host cellular functions beyond traditional AMGs.

• Why it matters: Understanding how phages reprogram bacteria is crucial for comprehending their ecological roles and potential applications, yet most studies focus on auxiliary metabolic genes (AMGs), leaving other tools like TSFs understudied.
• What they did: The review synthesizes genomic evidence for TSF prevalence, mechanistic insights into their influence on host transcription, and recent advances enabling large-scale bioinformatic analysis of TSFs in phages.
• The result: TSFs are positioned as AMG-complementary mechanisms that can be inferred from metagenomic data, with potential impacts on cellular and ecosystem functions, opening avenues for translational applications.