Fig. 3
From: Viral histones: pickpocket’s prize or primordial progenitor?
Viral histone doublets, triplets, and quadruplets. Configurations of predicted histone fold domain proteins in various viruses and metagenomic viral genomes. Green: H4-like; blue: H3-like; red: H2B-like; yellow: H2A-like; orange: no homology to any known protein