- Table lists the selected proteins identified by mass spectrometry associated with the linker histones H1.1, H1.2 and H1.X (color coded as indicated). Table lists the average number of peptides identified from each linker histone purification. The averages are derived from 2 to 4 replicates. * denotes proteins identified in histone H1.1 Mono-Q peak 2. = ALL H1’s (GROUP 1), = H1.1 AND H1.2 (GROUP 2), = H1.1 (GROUP 3), = H1.2 (GROUP 4), = H1.X (GROUP 5), = H1.1 AND H1.X (GROUP 6)