Aal proteins are similar to the 4-coumarate–CoA-ligase-like enzymes found in plants.
Two Aal proteins are constitutively expressed, while eight are upregulated by oleate.
Aal proteins are involved in peroxisomal fatty acid activation in Yarrowia lipolytica.
Aal4p and Aal6p presented substrate specificity for C16:1 and/or C18:0.