Lysine performs a significant role in calcium absorption, building muscle protein, and the physique’s manufacturing of hormones, enzymes, and antibodies. The exception to the rule is the DOT1 household, members of which methylate K79 within the globular area of histone H3 and which are structurally not related to SET-domain proteins 4 - 6 Recent work suggests that SET-domain-containing proteins methylate a few proteins in addition to histones (see later)