Fig. 2. Phylogenomic genome-BLAST distance phylogeny (GBDP) tree of Ca. Altiarchaeum viruses and viral proteins clusters.

a The tree was inferred using the distance formula D0 yielding average support of 69%. The numbers above branches are GBDP pseudo-bootstrap support values from 100 replications. The branch lengths of the resulting VICTOR⁹⁴ trees are scaled in terms of the respective distance formula used. The tree shows that the eight predicted viral genomes were assigned to the same family, to eight different genera, and ten species (which is the result of having multiple genomes included for Altivir_1_MSI and Altivir_2_MSI). b Protein clustering across all viruses revealed that Altivir_1_MSI_>0.1 µm_2018 and Altivir_6_ACLF, originating from different continents, have five protein clusters (2–6) in common. Altivir_2_MSI_BF_2012, Altivir_4_ACLF, and Altivir_8_HURL shared only one protein cluster (1). Open reading frames of the viral genomes were predicted using Prodigal v.2.6.3⁷⁴ and further translated with the R package seqinr v.3.6.-1. Colors indicate shared protein clusters between genomes and numbers show nonhypothetical consensus annotations according to Supplementary Data 3. Color code for viral genomes: Altivir_1_MSI = black, Altivir_2_MSI = blue, Altivir_3_ACLF = yellow, Altivir_4_ACLF = pink, Altivir_5_ACLF = orange, Altivir_6_ACLF = olive-green, Altivir_7_ACLF = pink-red, and Altivir_8_HURL = purple.