Members of this family are enzymes EC:2.3.1.-. involved in fatty acylation of the protoxins (HlyA) at lysine residues, thereby converting them to the active toxin. Acyl-acyl carrier protein (ACP) is the essential acyl donor. This family show a number of conserved residues that are possible candidates for participation in acyl transfer. Site-directed mutagenesis of the single conserved histidine residue in Swiss:P06736 resulted in complete inactivation of the enzyme [1].

1: HlyC, the internal protein acyltransferase that activates hemolysin toxin: role of conserved histidine, serine, and cysteine residues in enzymatic activity as probed by chemical modification and site-directed mutagenesis. Trent MS, Worsham LM, Ernst-Fonberg ML; Biochemistry 1999;38:3433-3439. PMID:10079090