The N-terminus end of the precursor protein has a sequence of 22 amino acids (mitochondrial targeting signal or MTS) before the second methionine, which is the first amino acid in peroxisomal Cat2p. The CAT2-encoded protein possesses, besides the MTS, a PTS- like tripeptide, AKL, at its C-terminus. As the MTS overrules the PTS, the protein encoded by the pHVX2-CAT2-mit construct is located in the mitochondrial matrix (mitochon- drial Cat2p or Cat2pmit). By comparison with the Cat2p of strain S288C, the VIN13 Cat2p shows five amino acid substitutions