Table 1. Summary of PTM abundance.

A) H1 canonical
Residue	-	S1	T3	S4	K16	S/T17	K21	K25	S28	K33	T34	S35	K45	S50	K51	K96	K109	S112	K167	S171	S186
N-term Acetylation	58%
Phosphorylation		22%	12%	27%		24%			7%		5%	6%								100%	100%
Acetylation					1%							<1%	1%	<1%	<1%			2%	3%
Monomethylation							2%	1%							1%
Dimethylation					2%					1%						1%	2%
Crotonylation															1%

The site, type and level of modification site occupancy of each PTM is indicated for each histone. For each PTM, the level of modification site occupancy is calculated by dividing the number of instances that a PTM was detected by the number of instances that a given amino acid was observed, providing an estimation of the relative abundance of each PTM. Sites of phosphorylation, which were detected only in IMAC/TiO₂ enriched fractions, are not listed. Residues are numbered starting with the first residue after the cleaved methionine. Canonical H1 (1A), H2A (1B), H2B (1C), H3 (1D), and H4 (1E) histones are shown which represent sequences common across all subtypes.