Table 2.

Residues with the most significant differences in interaction energies in three regions at the dimer-tetramer interface between H2A- and H2A.B-containing nucleosomes

Nucleosome region (Fig. 2)	Histone	Location	Residue	Mutated residues in H2A.B NCP	ΔΔEtotal (kcal/mol)
1	H2B	α2 helix	GLU73	none	2.0 ± 0.6
	H2B	α3 helix	LEU97	none	0.4 ± 1.1
	H4	α2 helix	ASP68	none	2.2 ± 0.3
	H4	α3 helix	ASP85	none	1.1 ± 0.2
	H4	α3 helix	LYS91	none	0.0 ± 1.2
	H4	α3 helix	ARG92	none	1.1 ± 1.9
	H4	α3 helix	TYR98	none	−0.2 ± 1.3
2	H2A	docking domain	THR101	none	0.5 ± 0.7
	H2A	docking domain	ALA103	SER103	−2.1 ± 0.8
	H3	α2 helix	GLU94	none	−0.1 ± 0.7
	H3	α2 helix	GLU97	none	0.8 ± 0.3
	H3	C-terminal tail	ARG134	none	2.0 ± 3.9
3	H2A	docking domain	ARG99	THR99	4.7 ± 1.7
	H2A	docking domain	LEU115	absent in H2A.B	6.3 ± 0.6
	H2A	docking domain	LYS118	absent in H2A.B	−0.9 ± 3.8
	H2A	docking domain	LYS119	absent in H2A.B	−0.6 ± 2.2
	H2A	C-terminal tail	GLU121	absent in H2A.B	3.8 ± 4.1
	H3	α2 helix	ASN108	none	0.0 ± 0.2
	H4	L1 loop	LYS44	none	0.0 ± 0.5

ΔΔE, interaction energies at the dimer-tetramer interface. Negative values correspond to locations that are more favorable in H2A.B systems, whereas positive values are more favorable in H2A nucleosomes.