title: Molecular characterization of HMW-GS 1Dx3(t) and 1Dx4(t) genes from Aegilops tauschii and their potential value for wheat quality improvement.
abstract: Two x-type high molecular weight glutenin subunits (HMW-GS) in Aegilops tauschii, 1Dx3(t) and 1Dx4(t) were identified by SDS-PAGE and MALDI-TOF-MS. Their complete coding sequences were isolated by AS-PCR. 1Dx3(t) and 1Dx4(t) genes consist of 2535 bp and 2508 bp and encode 845 and 836 amino acid residues, respectively. The deduced molecular masses of 1Dx3(t) and 1Dx4(t) gene products are 87655.26 Da and 86664.24 Da, respectively, well corresponding to the molecular masses measured by MALDI-TOF-MS. A total of 18 SNPs were identified between 1Dx3(t) and 1Dx4(t). Comparing with 1Dx5 subunit, 1Dx3(t) had a six amino acid insertion at 146-151 while the 1Dx4(t) had a nine amino acid deletion when compared with 1Dx3(t) subunit. The authenticity of the cloned 1Dx3(t) and 1Dx4(t) genes were confirmed by successful expression of their ORFs in E. coli. Comparison and phylogenetic tree based on the amino acid and nucleotide sequences confirmed that 1Dx3(t) was most closely related to 1Dx5 subunit that is widely accepted as a superior subunit for bread-making property. The secondary structure prediction demonstrated that 1Dx3(t) subunit has significantly high α-helix and β-strand contents, suggesting it might have positive effects on dough quality.
authors.affiliation: Key Laboratory of Genetics and Biotechnology, College of Life Science, Capital Normal University, Beijing, PR China.
authors.forename: K
authors.initials: K
authors.lastname: Wang
authors.forename: X L
authors.initials: XL
authors.lastname: An
authors.forename: L P
authors.initials: LP
authors.lastname: Pan
authors.forename: K
authors.initials: K
authors.lastname: Dong
authors.forename: L Y
authors.initials: LY
authors.lastname: Gao
authors.forename: S L
authors.initials: SL
authors.lastname: Wang
authors.forename: Z Z
authors.initials: ZZ
authors.lastname: Xie
authors.forename: Z
authors.initials: Z
authors.lastname: Zhang
authors.forename: R
authors.initials: R
authors.lastname: Appels
authors.forename: W
authors.initials: W
authors.lastname: Ma
authors.forename: Y M
authors.initials: YM
authors.lastname: Yan
mesh_terms: D000595:Amino Acid Sequence; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D017343:Genes, Plant; D005983:Glutens / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny; D020641:Polymorphism, Single Nucleotide; D017433:Protein Structure, Secondary; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D014908:Triticum / Q000145:classification / Q000235:genetics*
chemical_list: D021122:Protein Subunits; D005983:Glutens; C037302:glutenin