Sulfur-rich seed storage protein. This protein found in the seeds of many leguminous and non-leguminous plants is the source of sulfur-containing amino acids in seed meals. Hexamer; each subunit is composed of an acidic and a basic chain derived from a single precursor and linked by a disulfide bond (By similarity). Component of globulins complexes which accumulate in seeds (Probable). Accumulates during seed development. Causes an allergic reaction in human. Belongs to the 11S seed storage protein (globulins) family.