label: L-lysyl(27)-[histone H3] + 3 S-adenosyl-L-methionine = N(6),N(6),N(6)-trimethyl-L-lysyl(27)-[histone H3] + 3 S-adenosyl-L-homocysteine + 3 H(+)
label_lc: l-lysyl(27)-[histone h3] + 3 s-adenosyl-l-methionine = n(6),n(6),n(6)-trimethyl-l-lysyl(27)-[histone h3] + 3 s-adenosyl-l-homocysteine + 3 h(+)