Cloning of maize ferredoxin III gene: presence of a unique repetitive nucleotide sequence within an intron found in the 5'-untranslated region.

A genomic clone encoding the precursor of a non-photosynthetic ferredoxin (Fd III) from maize has been isolated and characterized. In comparison with the corresponding cDNA, the gene (fedIII) was found to be interrupted in the 5'-untranslated region by an intron consisting of 3,037 bp. About 80% of the total region of this intron is organized into four classes of tandemly repeated sequences with monomeric lengths of about 200 bp, 320 bp, 130 bp, and 90 bp. This unique intron organization is present in the fedIII gene of three related maize cultivars examined.