P2-like viruses (P2Vs), temperate phages of the Peduoviridae family, possess a lysogenic lifestyle that renders traditional isolation unsuitable, hindering our understanding of their diversity and ecological roles. Utilizing profile-hidden Markov models to analyze public databases, this study achieved four major advances: (1) Identified 5945 P2V genomes and built the P2V Genome Dataset (P2VGD), expanding known genomes 48-fold; (2) Phylogenetic classification into 13 superclades and 4671 genus-level clusters, a 106-fold diversity increase; (3) Identification of 757 auxiliary metabolic genes with biome-specific metatranscriptomic activities: human gut P2Vs encode antibiotic efflux and cell-wall remodeling enzymes, while oligotrophic marine P2Vs express glycan-scavenging enzymes; (4) Uncovering their widespread distribution across diverse biomes, dominated by host-associated environments but extending to under-sampled natural ecosystems. These findings greatly expand the genomic and functional understanding of P2Vs, highlighting their biological strategies in host adaptation, virus-host co-evolution, and microbiome dynamics.
Liu et al. (Mon,) studied this question.