Genomic organization of peanut allergen gene, Ara h 3.
Type 1 hypersensitivity to peanut proteins is a well-recognized health problem. Several peanut seed storage proteins have been identified as allergens. Ara h 3, a glycinin protein, is one of the important peanut allergens. Although amino acid and cDNA sequences are available for Ara h 3, there is not information at the genomic level. The objectives of this study were to isolate, sequence, and characterize the genomic clone of peanut allergen, Ara h 3. A peanut genomic library was screened, using two [32P] end-labeled oligonucleotide probes designed based on cDNA sequences of Ara h 3 and Ara h 4. Four positives lambda FIX II clones were obtained after four rounds of screenings. Digestion with Sac I resulted in two fragments of 1.5 and 10 kb hybridizing to the probes. Both fragments were subcloned into p-Bluescript vector and sequenced. The Ara h 3 gene spans 3.5 kb and consists of four exons, three introns, 5' and 3' flanking regions. The open reading frame is 2008 bp long and can encode a polypeptide of 538 amino acids residues. Sequences analogous to a TATA-box (TATAAAT), CAAT-box (AGGA), G-box (TCCTACGTGTCC) and several cis-elements were found in the promoter region. In the 3' downstream region, three polyadenylation signals (AATAAA) were identified.
Viquez
Olga M
OM
Food Biotechnology Laboratory, Department of Food and Animal Sciences, P.O. Box 1628, Alabama A and M University, Normal AL 35762, USA.
Konan
Koffi N
KN
Dodo
Hortense W
HW
D000485:Allergens / Q000235:genetics*; D052179:Antigens, Plant; D010367:Arachis / Q000276:immunology*; D001483:Base Sequence; D040461:Gene Components; D016678:Genome; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000276:immunology; D055314:Seed Storage Proteins; D017422:Sequence Analysis, DNA
D000485:Allergens; D052179:Antigens, Plant; D010940:Plant Proteins; D055314:Seed Storage Proteins; C118207:allergen Ara h3