Isolation and Characterization of 21.7 kDa prolamin gene from Foxtail millet (Setaria italica)

Abstract

Prolamins are the most distributed seed storage proteins in cereals. Prolamins are the main seed storage protein of foxtail millet (Setaria italica). The genomic and cDNA clone of a prolamin gene was isolated from foxtail millet. The isolated prolamin gene of foxtail millet lacks an intron based on a sequence contrast between the genomic and the cDNA clones. Semi-quantitative RT-PCR analysis showed a higher level of expression of the prolamin gene in an immature panicle. Physiochemical properties analysis based on the deduced amino acid sequence of foxtail millet prolamin gene showed that it codes for 204 amino acids, having a molecular weight of 21.7 kDa, pI 8.98 and GRAVY value 0.467. Homology search done with 21.7 kDa prolamin protein showed the highest similarity with α-zein of Setaria italic, Setaria viridis and Panicum miliaceum. The secondary structure predicted for the 21.7 kDa prolamin protein of foxtail millet indicates 14 coils and 15 helices. Like other prolamins, the 21.7 kDa prolamin protein is also deficient in the essential amino acid lysine.