Zeins are major seed storage proteins. The fl2 mutant remains anchored to endoplasmic reticulum membrane while the processed mature form localizes in the lumen. The floury-2 (fl2) mutation is associated with the synthesis of a novel 24 kDa alpha-zein storage protein and an altered protein body morphology. The 24 kDa protein is expressed as a 22 kDa alpha-zein 16 with an uncleaved signal peptide, resulting in an enhanced Lys content of the grain and a soft texture of the endosperm. Structurally, 22K and 19K zeins are composed of nine adjacent, topologically antiparallel helices clustered within a distorted cylinder. Belongs to the zein family.