title: Sequence and nitrate regulation of the Arabidopsis thaliana mRNA encoding nitrate reductase, a metalloflavoprotein with three functional domains.
abstract: The sequence of nitrate reductase (EC 1.6.6.1) mRNA from the plant Arabidopsis thaliana has been determined. A 3.0-kilobase-long cDNA was isolated from a lambda gt10 cDNA library of Arabidopsis leaf poly(A)+ RNA. The cDNA hybridized to a 3.2-kilobase mRNA whose level increased 15-fold in response to treatment of the plant with nitrate. An open reading frame encoding a 917 amino acid protein was found in the sequence. This protein is very similar to tobacco nitrate reductase, being greater than 80% identical within a section of 450 amino acids. By comparing the Arabidopsis protein sequence with other protein sequences, three functional domains were deduced: (i) a molybdenum-pterin-binding domain that is similar to the molybdenum-pterin-binding domain of rat liver sulfite oxidase, (ii) a heme-binding domain that is similar to proteins in the cytochrome b5 superfamily, and (iii) an FAD-binding domain that is similar to NADH-cytochrome b5 reductase.
authors.affiliation: Department of Biochemistry, Stanford University School of Medicine, CA 94305.
authors.forename: N M
authors.initials: NM
authors.lastname: Crawford
authors.forename: M
authors.initials: M
authors.lastname: Smith
authors.forename: D
authors.initials: D
authors.lastname: Bellissimo
authors.forename: R W
authors.initials: RW
authors.lastname: Davis
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites; D003579:Cytochrome Reductases; D003573:Cytochrome b Group; D042966:Cytochrome-B(5) Reductase; D015786:Cytochromes b5; D004247:DNA / Q000235:genetics / Q000302:isolation & purification; D005182:Flavin-Adenine Dinucleotide / Q000378:metabolism; D006418:Heme / Q000378:metabolism; D008969:Molecular Sequence Data; D008982:Molybdenum / Q000378:metabolism; D050901:Nitrate Reductase; D009565:Nitrate Reductases / Q000235:genetics*; D009566:Nitrates / Q000494:pharmacology*; D009693:Nucleic Acid Hybridization; D050862:Oxidoreductases Acting on Sulfur Group Donors; D010944:Plants / Q000201:enzymology* / Q000235:genetics; D011622:Pterins / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics*
chemical_list: D003573:Cytochrome b Group; D009566:Nitrates; D011622:Pterins; D012333:RNA, Messenger; D005182:Flavin-Adenine Dinucleotide; D006418:Heme; D008982:Molybdenum; D004247:DNA; D015786:Cytochromes b5; D003579:Cytochrome Reductases; D042966:Cytochrome-B(5) Reductase; D009565:Nitrate Reductases; D050901:Nitrate Reductase; D050862:Oxidoreductases Acting on Sulfur Group Donors