MSU-DOE Plant Research Laboratory, East Lansing 48824.
A cDNA clone encoding the peroxisomal enzyme glycolate oxidase (EC 1.1.3.15) was identified by probing a cDNA library of spinach with synthetic oligonucleotides based on the partial amino acid sequence of the enzyme. Determination of the DNA sequence of the 1526-nucleotide cDNA indicated a 1107-nucleotide open reading frame which encodes a polypeptide of 40,282 daltons. The polypeptide produced by in vitro transcription and translation of the cDNA insert had the same apparent subunit molecular mass as the enzyme purified from leaves, indicating that the cDNA encodes a full-length polypeptide and that no cleavage of the polypeptide is required for uptake of the polypeptide by peroxisomes. Comparison of the deduced amino acid sequence with those of two other plant peroxisomal proteins revealed a region of homology which may be involved in directing proteins to the peroxisome.