Fig. 3

Viral histone H3 gene in DSLPV1. a Schematic of viral histone H3 in DSLPV1 and its relatives in representative eukaryotes and other viruses. Different histone fold regions are marked in different colors, and the similar histones are indicated in the same color, i.e., eukaryotes derived histones in red, viral histones in pink and histone mimics in purple. b Amino acid sequence alignments of the DSLPV1 histone fold H3 and the representative eukaryotic histone H3 folds. Diverged amino acids are emphatically visualized and canonical helixes of histone fold are indicated. c Maximum likelihood phylogenetic tree of the viral and the representative eukaryotic histone fold H3 proteins. GenBank accession numbers of the histone sequences are listed in Additional file 1: Table S4. Only more than 50% of bootstrap value is shown in the tree. d Predicted three dimensional structure of the histone H3 fold in DSLPV1. The protein template used for the prediction is shown in blue and the target protein is in red