Peanut allergen Ara h I is a vicilin-like seed storage protein.
The primary DNA sequence of two of the largest cDNA clones
selected (41B and P17) was determined by Sanger dideoxy
sequencing using oligonucleotide primers directed to different
regions on the insert or a series of subclones constructed by
ExoIII digestion of the inserts. Clone 41B carried a 2,050-base
insert while clone P17 carried a 1,972 base insert. The first
ATG protein synthesis start codon was located at nucleotide
position 50-53. The sequence around this codon agrees with the
translation initiation sequence found in most eukaryotic rnRNAs
(21). Each of the inserts contained a large open reading frame
starting with this codon and ending with a TGA codon at nucleotide position 1928-1930. Overall, there was > 97% DNA sequence
homology between the two inserts.
Both clones were capable of encoding a protein of - 68
kD. The amino acid sequence that was determined from Ara h
I peptides I and III is found in both of these clones. The only
difference between the derived and predicted amino acid sequence
of both clones occurs at position seven of peptide II in
clone P17. At this position there is a glycine residue in the
peptide that is missing in the P17 DNA sequence. In addition,
both proteins have a signal peptide at the amino terminus (22)
and a single glycosylation addition site (NAS) at amino acid
position 521-523. These data confirm and extend our conclusion
that these clones encode the Ara h I allergen.