Catalyzes the trimethylation of 'Lys-116' in calmodulin. [calmodulin]-L-lysine + S-adenosyl-L-methionine = [calmodulin]-N(6)-methyl-L-lysine + H(+) + S-adenosyl-L-homocysteine Monomer (Probable). Interacts with HSP90, probably as a client (By similarity). Belongs to the class I-like SAM-binding methyltransferase superfamily. CLNMT methyltransferase family.