title: Diversification of 13S globulins, allergenic seed storage proteins, of common buckwheat.
abstract: The α polypeptide of the 13S globulin subunit of common buckwheat is the counterpart of the major allergenic β polypeptide. Trypsin digestibility varies between variants of the α polypeptide with and without a tandem repeat insert. To evaluate the intra-species diversity of 13S globulin, the comprehensive screening of a genomic DNA library was performed, resulting in the isolation of 14 and 3 genes for Met-poor and Met-rich subunits, respectively. Although most tandem repeat units were 45 bp in length, the two-repeat gene Glb2B and all one-repeat genes contained an additional 3 bp. Secondary structure predictions and polyacrylamide gel electrophoresis demonstrated that the sense strand of Glb2B-CCG, the additional 3 bp-deletion clone of Glb2B, formed a more rigid secondary structure than that of the wild-type. Thus, the large intra-species variation of 13S globulin revealed in this study and its diversification might be attributable to the unique nature of the tandem repeat sequences.
authors.affiliation: Graduate School of Agriculture, Kyoto University, Kitashirakawa, Kyoto 606-8502, Japan.
authors.forename: Madoka
authors.initials: M
authors.lastname: Sano
authors.affiliation: Graduate School of Agriculture, Kyoto University, Kitashirakawa, Kyoto 606-8502, Japan.
authors.forename: Mariko
authors.initials: M
authors.lastname: Nakagawa
authors.affiliation: Graduate School of Agriculture, Kyoto University, Kitashirakawa, Kyoto 606-8502, Japan.
authors.forename: Akifumi
authors.initials: A
authors.lastname: Oishi
authors.affiliation: Graduate School of Agriculture, Kyoto University, Kitashirakawa, Kyoto 606-8502, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Yasui
authors.affiliation: Graduate School of Agriculture, Kyoto University, Kitashirakawa, Kyoto 606-8502, Japan. Electronic address: tanakato@kais.kyoto-u.ac.jp.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Katsube-Tanaka
mesh_terms: D000485:Allergens / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D001483:Base Sequence; D019612:Fagopyrum / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D005916:Globulins / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D008969:Molecular Sequence Data; D055314:Seed Storage Proteins / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D012639:Seeds / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D016415:Sequence Alignment; D020080:Tandem Repeat Sequences
chemical_list: D000485:Allergens; D005916:Globulins; D055314:Seed Storage Proteins
keywords: 13S globulin; Allergen; Common buckwheat; Secondary structure; Tandem repeat