Diversity of Hyperthermophilic Archaeal Viruses

David Prangishvili, Mart Krupovic, Diana P.Baquero

Institut Pasteur, Paris, France Ivane Javakhishvili Tbilisi State University, Tbilisi, Georgia.

Abstract

Extreme thermal environments represent a habitat for viruses with remarkable morphological diversity and unique genome contents, many of which have not been described in moderate temperature environments. Most of these viruses infect hyperthermophilic archaea of the phylum Crenarchaeota and are currently classified into 13 families. Here, we summarize the state-of-the-art knowledge on the diversity and virion structures of crenarchaeal viruses. We then highlight the genomic features of hyperthermophilic archaeal viruses and emphasize how structural and functional genomic approaches have shed light into the characterization of viral proteins. We finally discuss the origins and evolutionary relationships between crenarchaeal viruses, underpinning their distinctiveness in the global virosphere.

Key words: Archaea, Crenarchaea, Diversity, Genomics, Hyperthermophilic environments, Morphologies, Virion structures, Viruses.