University of Miami researchers have identified previously unknown viruses that they say may bridge an evolutionary gap between viruses and encapsulins, cellular protein compartments. The university reports that the findings, published in Nature Communications, challenge the idea that encapsulins simply evolved from viruses. The team interprets them as evidence that viruses and encapsulins evolved from one another repeatedly over millions of years.
At the center are HK97-fold proteins, which assemble into shells in both viruses and encapsulins. According to the university, the newly identified viruses have genomes smaller and simpler than those of other viruses with HK97-fold shells and share features with encapsulins. First author Abelardo Aguilar says these shells can enclose biochemical reactions in cellular lineages, while in viruses they store and protect viral genomes.
Aguilar and colleagues, working under senior author Antoni Luque Santolaria, used bioinformatics, biophysical models, protein language models and AlphaFold to mine structural information from databases containing billions of DNA sequences. Those sequences came from samples including soil, seawater, wastewater and the human gut, the university says.
The university reports that the study also outlines a potential mechanism involving procapsids, or immature viral shells, that could allow evolutionary transitions and carry both genomic and metabolic roles. Aguilar also raised the possibility that viral capsids could facilitate biochemical reactions.
Comments