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Article
The Role of Proteolysis in the Processing and Assembly of 11S Seed Globulins
The Plant Cell (1998)
  • Rudolf Jung, United States Department of Agriculture–Agricultural Research Service, Purdue University
  • Marvin Paul Scott, United States Department of Agriculture–Agricultural Research Service, Purdue University
  • Young-Woo Nam, United States Department of Agriculture–Agricultural Research Service, Purdue University
  • Todd W. Beaman, United States Department of Agriculture–Agricultural Research Service, Purdue University
  • Ronald Bassüner, United States Department of Agriculture–Agricultural Research Service, Purdue University
  • Isolde Saalbach, Institute of Plant Genetics and Crop Plant Research-Gatersleben,Germany
  • Klaus Muntz, Zentralinstitut für Genetik und Kulturpflanzenforschung
  • Niels C. Nielsen, United States Department of Agriculture–Agricultural Research Service, Purdue University
Abstract
11S seed storage proteins are synthesized as precursors that are cleaved post-translationally in storage vacuoles by an asparaginyl endopeptidase. To study the specificity of the reaction catalyzed by this asparaginyl endopeptidase, we prepared a series of octapeptides and mutant legumin B and G4 glycinin subunits. These contained amino acid mutations in the region surrounding the cleavage site. The endopeptidase had an absolute specificity for Asn on the N-terminal side of the severed peptide bond but exhibited little specificity for amino acids on the C-terminal side. The ability of unmodified and modified subunits to assemble into hexamers after post-translational modification was evaluated. Cleavage of subunits in trimers is required for hexamer assembly in vitro. Products from a mutant gene encoding a noncleavable prolegumin subunit (LeBΔN281) accumulated as trimers in seed of transgenic tobacco, but products from the unmodified prolegumin B gene accumulated as hexamers. Therefore, the asparaginyl endopeptidase is required for hexamer assembly.
Publication Date
March, 1998
DOI
​10.​1105/​tpc.​10.​3.​343
Publisher Statement
This article is from The Plant Cell 10 (1998): 343, doi: ​10.​1105/​tpc.​10.​3.​343. Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.
Citation Information
Rudolf Jung, Marvin Paul Scott, Young-Woo Nam, Todd W. Beaman, et al.. "The Role of Proteolysis in the Processing and Assembly of 11S Seed Globulins" The Plant Cell Vol. 10 Iss. 3 (1998) p. 343 - 357
Available at: http://works.bepress.com/paul-scott/3/