Additional file 1:

Consensus sequence cartoon of histone H3 (long branching sequences removed) and aligned protein sequences of 128 H3 variants. Amino acid positions refer to human H3.1. Identical sites are shaded in black, similar residues are shaded in light grey. The positions of four helix motifs within the histone fold domain and the putative chaperone recognition domain are marked at the top of the alignment.

Format: JPEG Size: 2.9MB Download file

Additional file 2:

Phylogenetic tree of eukaryotic life (simplified after [23]). The position of selected species is highlighted.

Format: JPEG Size: 308KB Download file

Additional file 3:

FASTA formatted histone H3 variant sequence alignment.

Format: FAST Size: 30KB Download file

Additional file 4:

Overview about the most frequent residue alterations in various ancestral state sequences of histone H3 (compare Figure 3). Variable sites are highlighted (*); symbols beneath list the most frequent amino acid variations. Outgroup taxons used for ancestral state reconstruction a displayed within brackets for each clade.

Format: JPEG Size: 1.7MB Download file

Additional file 5:

The alignment contains some exemplary N-terminal chromodomain sequences of putative Hp1-like proteins from putatively early branching eukaryotes, which possess a set of conserved residues (*) formally required for ARKme3S/T binding. Residues identical in 85% of all sequences are shaded black; residues similar in 85% of all sequences are shaded grey. Notably, in three Trichomonas vaginalis sequences a C-terminal chromoshadowdomain could be recognized (C+CS).

Format: JPEG Size: 386KB Download file