The Characteristics, Structures and Evolutionary Relationships of Prolamins

Can We Improve the Nutritional Quality of Legume Seeds?

“…Few studies have been carried out on engineering the properties of legume globulins to alter functional behavior, but those of Utsumi's group Utsumi et al, 2002) have given valuable insights into the relationship between structure and functionality for soybean proteins. The lack of Cys and Met in legume seed globulins can readily be overcome in feed production by mixing with cereal protein (which has a complementary composition; Shewry and Tatham, 1999), but is still regarded as a target for improvement (Krishnan, 2000). Legume proteins are especially poor for ruminant nutrition, however, because the protein is degraded in the rumen.…”

Protein Storage Bodies and Vacuoles

“…These PBs can become sequestered into provacuoles that eventually fuse, forming one or more large central vacuoles that contain numerous protein accretions (Levanony et al, 1992;Galili et al, 1993;see Marty, 1999, in this issue). The assembly of prolamins to form PBs within the ER undoubtedly reflects the unusual structures of these proteins (reviewed in Shewry and Tatham, 1998).…”

“…In the past, the terms PB and PSV have been used interchangeably, but PSV is now used to differentiate vacuoles containing storage proteins from PBs originating from the ER. Our understanding of the cellular context in which storage proteins accumulate derives from many significant advances in gene structure and regulation, as well as the biochemistry and morphogenesis of storage tissues (reviewed in Chrispeels, 1991;Thomas, 1993;Staswick, 1994;Shewry et al, 1995;Galili and Herman, 1997;Nielsen et al, 1997;Shewry and Tatham, 1998; see also Battey et al, 1999;Marty, 1999;Sanderfoot and Raikhel, 1999;Vitale and Denecke, 1999, in this issue).…”

The Critical Role of Disulfide Bond Formation in Protein Sorting in the Endosperm of Rice

“…Although this classification is convenient in terms of protein handling, it does not necessarily reflect the evolutionary relationships between storage proteins. For example, Kreis et al (1985) reported that prolamins, a major class of seed storage proteins in cereals (Shewry and Tatham, 1999), and water-soluble 2S albumins in dicotyledonous plants contain homologous sequences in three separate regions, termed A, B, and C. The three-dimensional structures of 2S albumins in sunflower (Helianthus annuus; SFA-8) (Pandya et al, 2000;Pantoja-Uceda et al, 2004) and castor bean (Ricinus communis; RicC3) (Pantoja-Uceda et al, 2003) revealed that these proteins are part of a superfamily of proteins whose structure is described as ''4 helices; folded leaf; right-handed superhelix; disulfide rich'' (Murzin et al, 1995).…”