Next, we aimed to target H2BK43 or H2BK46, which is located near the C-terminus of LANA rather than the N-terminus. Based on the co-crystal structure of nucleosome-LANA (PDB: 1ZLA), A16 or P17 on LANA is closer to H2BK43 than G15 (Figure ). We thus substituted A16 or P17 with Orn and conjugated it with BAHA (Figure ). However, both catalysts mainly acetylated H2BK120, rather than H2BK43 or H2BK46 (Figure ). This result suggested that both H2BK43/K46 and H2BK120 were within CER of the catalysts, but H2BK120 was preferentially acylated due to higher reactivity of H2BK120 than H2BK43/K46 (Figure ). In order to realize H2BK43-or H2BK46-selective acylation, other Lys residues of higher reactivity, such as H2BK120 and H2BK108, must be excluded from CER.