|  | Class a: All alpha proteins [46456] (284 folds) | 
|  | Fold a.22: Histone-fold [47112] (1 superfamily) core: 3 helices; long middle helix is flanked at each end with shorter ones | 
|  | Superfamily a.22.1: Histone-fold [47113] (5 families)  | 
|  | Family a.22.1.1: Nucleosome core histones [47114] (6 proteins) form octamers composed of two copies of each of the four histones | 
|  | Protein Histone H4 [47125] (7 species) | 
|  | Species Baker's yeast (Saccharomyces cerevisiae) [TaxId:4932] [68987] (1 PDB entry) | 
|  | Domain d1id3b_: 1id3 B: [66113] Other proteins in same PDB: d1id3a_, d1id3c_, d1id3d_, d1id3e_, d1id3g_, d1id3h_ protein/DNA complex; complexed with mn | 
|  | Domain d1id3f_: 1id3 F: [66117] Other proteins in same PDB: d1id3a_, d1id3c_, d1id3d_, d1id3e_, d1id3g_, d1id3h_ protein/DNA complex; complexed with mn | 
Timeline for Species Baker's yeast (Saccharomyces cerevisiae) [TaxId:4932] from a.22.1.1 Histone H4: