Numerous cultivated and uncultivated viruses encode ribosomal proteins

Area of Science:

• Virology
• Molecular Biology
• Ecology

Background:

• Viruses alter host metabolism via auxiliary metabolic genes.
• Viral genomes were not known to encode core translation machinery like ribosomal proteins (RPs).

Purpose of the Study:

• To investigate the presence and function of ribosomal proteins (RPs) in viral genomes.
• To understand the ecological distribution and evolutionary implications of virus-encoded RPs.

Main Methods:

• Analysis of reference viral genomes and global viral metagenomic datasets.
• Identification and characterization of viral RP genes.
• Functional assays using Escherichia coli to test RP incorporation into ribosomes.
• Ecological distribution analysis of virus-encoded RPs.

Main Results:

• Identified 14 distinct ribosomal proteins (RPs) encoded across diverse viral genomes.
• Virus-encoded RPs, particularly bS21 and bL12, can be incorporated into functional 70S ribosomes.
• Distinct subsets of RPs are enriched in aquatic viruses and viruses of animal-associated bacteria, suggesting ecosystem-specific adaptations.
• Viral RP genes are under purifying selection, indicating retained function after horizontal gene transfer.

Conclusions:

• Viruses encode and utilize ribosomal proteins (RPs), expanding our understanding of viral genetic capabilities.
• Virus-encoded RPs can integrate into host translation machinery, potentially modulating host metabolism and ecosystem interactions.
• The presence and distribution of viral RPs suggest functional importance and adaptation to specific ecological niches.