MS-based proteomic characterization of pacmanvirus lostcity virions

The microbial sampling of submarine hydrothermal vent remains challenging, with even fewer studies focused on viruses. Here we report the first isolation of a eukaryotic virus from the Lost City hydrothermal field, by co-culture with the laboratory host Acanthamoeba castellanii. This virus, named pacmanvirus lostcity, is closely related to previously isolated pacmanviruses (strains A23 and S19), clustering in a divergent clade within the long-established family Asfarviridae. Its icosahedral particles are 200 nm in diameter, with an electron-dense core surrounded by an inner membrane. Its genome of 395,708 bp (33% G+C) is predicted to encode 473 proteins. However, besides these standard properties, pacmanvirus lostcity was found associated with a new type of selfish genetic element (pltv), 7 kb in length, whose architecture and gene content are reminiscent of those of transpovirons, hitherto specific to the family Mimiviridae. We performed MS-based proteomic analyses of purified virions to characterize its protein content.