Different roles of the two components of human protein O-mannosyltransferase, POMT1 and POMT2

► POMTs have conserved amino acids from bacterium to human. ► We examine the importance of conserved three amino acids in human POMTs. ► Amino acid substitution in POMT1 abolished enzymatic activity but not in POMT2. ► POMT1 and POMT2 have different roles.