Analysis of the cross-taxa Pfam domains.

<p>(<b>A</b>) Partition of the 667 Pfam families according to the ratio of the viral proteins to all the proteins that belong to the family (in %). The vast majority (82%) of the Pfam families contain ≤5% of viral proteins (blue). (<b>B</b>) Partition of the Pfam families in which the viral proteins are clustered. VC, a cluster that includes only viral proteins in a sub-tree; #VC, the number of Viral Clusters. The analysis covers the Pfam families that contain ≤5% of viral proteins (blue slice from A). We consider only 335 Pfam families that contain the families with (i) only one VC (41%), (ii) 19% with exactly 2 VCs and (iii) 4% with ≤10 VCs but with a condensation factor ≥3 (#Vir/#VC). Using this filtration additional 36% of the families were removed (marked, others). (<b>C</b>) Alignment tree of IL-6 Pfam family (PF00489). The family contains 10 viral proteins (blue font), 2 viral clusters (#VC, blue font sub-trees) and 136 metazoan proteins. Collapsed sub-trees are represented by a triangle indicating the number of proteins as the tree leafs. The maximal leaves in this tree are 19 (in the collapsed sub-tree, red triangle). The deepest viral protein in the tree is of depth 9, and thus the normalized (norm.) depth is 9/19 = 0.474. The depth of the viral cluster (VC, the maximal sub-tree which contains only viral proteins) is 4/19 = 0.211. (<b>D</b>) The distribution of normalized depths of all proteins for the 335 Pfam families (top) and the distribution of the depths of the viral proteins in these families (bottom).