Allantoin metabolism-specific malate synthase involved in the recycling the glyoxylate generated during allantoin degradation by the ureidoglycollate (UG) hydrolase reaction. acetyl-CoA + glyoxylate + H2O = (S)-malate + CoA + H(+) Interacts with PEX9. Imported in peroxisome via recognition by the peroxisomal targeting signal receptor PEX9. Expression is insensitive to carbon catabolite repression, but highly sensitive to nitrogen catabolite repression (PubMed:8462696). Its expression is induced by allophanate or oxalurate (PubMed:3915539). Diminishes the ureidoglycollate hydrolase activity by 3 to 4 fold. Belongs to the malate synthase family.