N(6)-methyl-L-lysyl-[histone] + S-adenosyl-L-methionine = N(6),N(6)-dimethyl-L-lysyl-[histone] + S-adenosyl-L-homocysteine + H(+)
n(6)-methyl-l-lysyl-[histone] + s-adenosyl-l-methionine = n(6),n(6)-dimethyl-l-lysyl-[histone] + s-adenosyl-l-homocysteine + h(+)
N(6)-methyl-L-lysyl-[histone] + S-adenosyl-L-methionine = N(6),N(6)-dimethyl-L-lysyl-[histone] + S-adenosyl-L-homocysteine + H(+)
n(6)-methyl-l-lysyl-[histone] + s-adenosyl-l-methionine = n(6),n(6)-dimethyl-l-lysyl-[histone] + s-adenosyl-l-homocysteine + h(+)