15A-12 |
Sequence of a major peanut allergen Ara h2 reveals the presence of isoforms of the gene in the peanut genome. |
O. M. VIQUEZ and H. W. Dodo. Dept. of Food & Animal Sciences, Alabama A&M Univ., Food Biotechnology Lab., PO Box 1628, Normal, AL 35762 Food allergy is a serious health problem affecting several million people in the United States alone. Despite its nutritional value, peanut is one of the most common food allergen. Peanut allergy is increasing and is responsible for severe symptoms leading sometime to death. As a preliminary to silence the genes encoding the major peanut allergens, it is important to sequence and characterize their genomic clones and analyze their structural and regulatory features. The objectives of this research was to isolate, sequence and molecularly characterize at least one full length genomic clone encoding a major allergen Ara h2. A lambda fix II genomic library constructed from seed DNA of Arachis hypogaea (F78-1339) was screened with an 80-bp synthetic oligonucleotide designed based on nucleotides 11-91 of the published cDNA sequence of Ara h2. A positive lambda clone with a 16 kb insert was isolated, digested with BamH I, subcloned in pBluescript SK (+/-) vector, sequenced and characterized. Sequence analysis revealed a full-length genomic clone with an open reading frame of 622 nucleotides, a deduced amino acid content of 207 residues and a putative signal peptide of 21 amino acid residues. A putative polyadenylation signal (AATAAA) is located at position 951 in the untranslated region of the gene. In the proximal region, a putative TATA box (TATTATTA) is present at position –72 with respect to the initiation codon. Comparison of the genomic and cDNA sequences of Ara h2 reveals the absence of an intron and the presence of at least two isoforms or two different members of the same gene family in the peanut genome.
Session 15A, Biotechnology
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