label: phosphoethanolamine + 3 S-adenosyl-L-methionine => phosphocholine + 3 S-adenosyl-L-homocysteine + 3 H(+)
label_lc: phosphoethanolamine + 3 s-adenosyl-l-methionine => phosphocholine + 3 s-adenosyl-l-homocysteine + 3 h(+)