Hydroxyacid Oxidase 2 (HAO2)

HAO2 is one of three related genes that have 2-hydroxyacid oxidase activity yet differ in encoded protein amino acid sequence, tissue expression and substrate preference. Subcellular location of the encoded protein is the peroxisome. Specifically, this gene is expressed predominantly in liver and kidney and has the highest activity toward the substrate 2-hydroxypalmitate. The predicted 351-amino acid HAO2 protein, which the authors called HAOX2, terminates in the consensus type 1 peroxisomal targeting signal (PTS1) serine-arginine-leucine. Indirect immunofluorescence indicated that HAO2 localizes to the peroxisome. HAO2 shares 46.7% amino acid sequence identity identity with spinach GOX and 46.0% identity with HAO1. Recombinant HAO2 had 2-hydroxyacid oxidase activity, with highest activity toward 2-hydroxypalmitate.