Tissue-specific and developmental regulation of a gene encoding a low molecular weight sulfur-rich protein in soybean seeds.

A gene corresponding to a cDNA clone, SE60, encoding a low molecular weight sulfur-rich protein in soybean seeds was isolated from a soybean genomic library and characterized at the nucleotide level. The SE60 gene is interrupted by an intervening sequence of 694 bp in size. The 5' flanking region of the gene contained various regulatory sequences such as the RY repeat and CACA elements found in other seed protein genes of legumes. The SE60 gene encoded a preprotein of 75 amino acids, having a signal sequence of 28 amino acids at the N-terminus. The mature protein of 47 amino acids was basic and cysteine-rich. Northern blot analysis suggested that the SE60 gene is expressed in a tissue-specific and developmentally regulated manner during soybean seed development. The SE60 genes form a small multigene family composed of about four members in the soybean genome.