Resurrection of a global, metagenomically defined gokushovirus

Gokushoviruses are single-stranded, circular DNA bacteriophages found in
metagenomic datasets from diverse ecosystems wordwide, including human gut
microbiomes. Despite their ubiquity and abundance, little is known about
their biology or host range: isolates are exceedingly rare, known only
from three obligate intracellular bacterial genera. By synthesizing
circularized phage genomes from prophages embedded in diverse enteric
bacteria, we produced gokushoviruses in an experimentally tractable model
system, allowing us to investigate their features and biology. We
demonstrate that virions can reliably infect and lysogenize hosts by
hijacking a conserved chromosome-dimer resolution system. Sequence motifs
required for lysogeny are detectable in other metagenomically defined
gokushoviruses; however, we show that even partial motifs enable phages to
persist cytoplasmically without leading to collapse of their host culture.
This ability to employ multiple, disparate survival strategies is likely
key to the long-term persistence and global distribution of
Gokushovirinae.