Identification and DNA sequence analysis of a γ-type gliadin cDNA plasmid from winter wheat.

Recombinant cDNA plasmids possessing the coding sequences for the γ-type gliadins were isolated from a cDNA library prepared from wheat seed poly (A(+)) RNA. One of these plasmids, pGliB48, specifically hybridizes to poly (A(+)) RNA molecules 1 400-1 500 bases in length that direct the synthesis of polypeptides at 38 Kd and 46 Kd, the latter size characteristic of the γ-type gliadins. The cDNA sequence of pGliB48 was determined and encompasses the 3' untranslated region as well as 245 amino acids from the C-terminus of the γ-type gliadin polypeptide. The 5'-end of the DNA coding sequence consists of a tandem repeat unit composed of eight amino acids. Localized regions of homology are observed for the α/β-type and γ-type gliadin cDNA sequences.