THE GENOMIC ORGANIZATION OF THE GENE ENCODING A NITRATE-INDUCIBLE FERREDOXIN-NADP(+) OXIDOREDUCTASE FROM RICE ROOTS

A genomic clone of the gene encoding a nitrate-inducible ferredoxin-NADP(+) oxidoreductase (FNR) from rice (Oryza sativa L.) roots has been isolated and its nucleotide sequence determined. The clone contains 3897 nucleotides of the gene which consists of six exons interrupted by five introns. The transcription start site was determined by primer extension analysis which locates 64 bp upstream of the ATG translation initiation codon. The 5'-flanking region contains canonical TATA- and CAAT-boxes, and a potential Sp1-binding site. Four ATCAA(A/C) and two inverted TTTGAT sequences are localized in the promoter region and a TGTAA motif occurs three times in the 3'-untranslated region. No significant similarity was found when the 5' flanking region was compared with that of the photosynthetic FNR gene.