Convergent evolution of viral-like Borg archaeal extrachromosomal elements and giant eukaryotic viruses.

ABSTRACT: Borgs are huge extrachromosomal elements of anaerobic methane-oxidizing archaea. They exist in exceedingly complex microbiomes, lack cultivated hosts and have few protein functional annotations, precluding their classification as plasmids, viruses or other. Here, we use in silico structure prediction methods to investigate potential roles for ~10,000 Borg proteins. Prioritizing analysis of multicopy genes that could signal importance for Borg lifestyles, we uncover highly represented de-ubiquitination-like Zn-metalloproteases that may counter host targeting of Borg proteins for proteolysis. Also prevalent are clusters of multicopy genes for production of diverse glycoconjugates that could contribute to decoration of the host cell surface, or of putative capsid proteins that we predict mult

SUBMITTER: Banfield JF 

PROVIDER: S-EPMC12660748 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature