Nucleotide and deduced amino acid sequence of a putative higher molecular weight precursor for catalase in sunflower cotyledons.

A cDNA from a sunflower (Helianthus annuus L.) library encoded a 56.8 kDa catalase peptide. N-terminal sequence comparisons to peroxisomal higher molecular weight precursors revealed conserved amino acid motifs around the (putative) cleavage sites. These findings suggest that the 55 kDa catalase in sunflower cotyledons is synthesized at a higher molecular weight.