Characterization of soybean vegetative storage proteins and genes.

Soybean vegetative storage proteins (VSPs) were purified and characterized. Anion exchange HPLC resolved partially purified VSPs into fractions containing 27-kD/27-kD and 29-kD/29-kD homodimers and 27-kD/29-kD heterodimers. Reversed-phase HPLC resolved partially purified VSPs into three fractions. One fraction contained only 27-kD VSP and the other two contained 29-kD VSP. The two 29-kD VSP fractions differed with respect to their cyanogen bromide cleavage patterns, an observation that indicated the 29-kD VSPs were heterogeneous. Genomic clones that contained 29-kD VSP genes were also isolated and characterized. One genomic clone contained a complete 29-kD VSP gene and was sequenced. The coding region in the clone contained two introns whose borders had regulatory sequences typical of other eukaryotic genes. Putative polyadenlyation signals were present in the 3'-flanking region of the gene, while putative TATA, CAAT, and enhancer core sequences were found in the 5'-flanking regions. A second genomic clone that was studied contained the 5' regions of two partial 29-kD VSP genes in an inverted linkage. Genomic DNA gel blots showed that the two genes were organized in the same arrangement in the soybean genome.