Nucleic and Amino Acid Sequences Support Structure-Based Viral Classification.

Area of Science:

• Virology
• Structural Biology
• Bioinformatics

Background:

• Viral capsids protect viral genomes and exhibit strong evolutionary conservation.
• A structure-based classification of viruses has been proposed but lacked strong sequence support.
• Structural convergence was a potential explanation for observed capsid similarities.

Purpose of the Study:

• To investigate if undetected sequence similarities support a structure-based viral capsid classification.
• To explore both amino acid and nucleotide sequence similarity for evolutionary insights.
• To identify candidate genes for viral capsid proteins, such as for Pandoravirus.

Main Methods:

• Comparative sequence analysis of viral capsid proteins.
• Searched for both amino acid and nucleotide sequence similarities.
• Utilized a structure-based classification framework for viral capsids.

Main Results:

• Detected significant amino acid and nucleotide sequence similarities among viral capsid proteins.
• Confirmed that sequence similarities strongly support the structure-based classification.
• Identified a candidate gene for the Pandoravirus capsid protein.

Conclusions:

• The structure-based classification of icosahedral viral capsids is supported by common descent, evidenced by sequence similarities.
• Nucleotide sequence similarities were found across viruses infecting all three domains of life.
• This study bridges sequence and structure analyses for understanding macromolecular function and evolution.