– Histone H2B (108-125) is a peptide fragment of histone H2B that corresponds to amino acid residues 109-126 of the human histone H2B sequence. It contains an N-terminal biotinylated lysine followed by a tryptophan linker. Histone H2B can be modified by addition of an O-linked N-acetylglucosamine (GlcNAc) moiety to the serine residue at position 112, which promotes monoubiquitination of the lysine at position 120.1 Both of these modifications are associated with active transcription. Histone H2B also has lysine residues at positions 108, 116, and 120 that are subject to acetylation.2