Powerful sequence similarity search methods and in-depth manual analyses can identify remote homologs in many apparently "orphan" viral proteins
D. Kuchibhatla, W. Sherman, B. Chung, S. Cook, G. Schneider, B. Eisenhaber, D. Karlin, Journal of Virology 88 (2014) 10–20.
LibreCat: https://research-explorer.ista.ac.at/record/2250
DOI: 10.1128/JVI.02595-13