Novel type of virus found in a lake in Central Finland links virus groups

A few years ago during a laboratory course in University of Jyväskylä a new bacterial virus infecting a Flavobacterium host was isolated from a water sample taken from Lake Jyväsjärvi, Finland. A more detailed analysis done in collaboration with scientists from Universities of Jyväskylä, Helsinki and Oxford revealed the unique characteristics of this virus. The virus, named FLiP, was found to be the first described virus with an icosahedral capsid, internal lipid membrane and a single stranded DNA genome.

Without the detailed near-atomic resolution structural analysis the exceptional characteristics of FLiP could have remained unnoticed. Whereas the virus genome showed limited sequence

similarity to other known viruses, the structure of the viral major capsid protein was strikingly similar to that observed in double stranded DNA viruses of the PRD1-adenovirus lineage. FLiP is the first ssDNA virus assigned in this lineage. These results suggest that the capsid protein structure could be used to complement the sequence data when classifying viruses and in detecting their deep evolutionary relationships.

Furthermore, the finding of FLiP exemplifies the importance of detailed characterization of novel viruses from diverse environments in detail to understand the diversity of the microbial world.

The study was publisher in Proceedings of National Academy of Sciences of the United States of America (PNAS).