S-adenosyl-L-methionine-dependent protein-lysine N-methyltransferase that methylates elongation factor 1-alpha (TEF1 and TEF2) at 'Lys-390'. Present with 1760 molecules/cell in log phase SD medium. Belongs to the class I-like SAM-binding methyltransferase superfamily. METTL21 family. EFM6 subfamily.