Yaravirus brasiliense genomic structure analysis and its possible influence on the metabolism.

Here we analyze the Yaravirus brasiliense, an amoeba-infecting 80-nm-sized virus with a 45-kbp dsDNA, using structural molecular modeling. Almost all of its 74 genes were previously identified as ORFans. Considering its unprecedented genetic content, we analyzed Yaravirus genome to understand its genetic organization, its proteome, and how it interacts with its host. We reported possible functions for all Yaravirus proteins. Our results suggest the first ever report of a fragment proteome, in which the proteins are separated in modules and joined together at a protein level. Given the structural resemblance between some Yaravirus proteins and proteins related to tricarboxylic acid cycle (TCA), glyoxylate cycle, and the respiratory complexes, our work also allows us to hypothesize that these viral proteins could be modulating cell metabolism by upregulation. The presence of these TCA cycle-related enzymes specifically could be trying to overcome the cycle's control points, since they are strategic proteins that maintain malate and oxaloacetate levels. Therefore, we propose that Yaravirus proteins are redirecting energy and resources towards viral production, and avoiding TCA cycle control points, "unlocking" the cycle. Altogether, our data helped understand a previously almost completely unknown virus, and a little bit more of the incredible diversity of viruses.