Structural variation and evolutionary relationship of novel HMW glutenin subunits from Elymus glaucus.
High molecular weight (HMW) glutenin subunits (GS) are important seed storage proteins relevant to the end-use quality of wheat and other cereal crops. Here we report the isolation and characterization of two novel HMW-GS alleles (1St 1.4 and 1St1.1) from the perennial Triticeae species Elymus glaucus. The amino acid (aa) sequences of E. glaucus 1St1.4 and 1St1.1 were predicted as 434 aa and 358 aa, respectively. Both subunits comprise a signal peptide with a conserved N-terminal domain, a central repetitive domain and a C-terminal domain. Elymus glaucus 1St 1.4 and 1St1.1 exhibit several distinct characteristics different from other known HMW-GSs. The lengths of repetitive domains in E. glaucus 1St 1.4 and 1St1.1 are substantially smaller than those of other known HMW-GSs, in which 1St1.1 (only 358 aa) is the smallest subunit identified so far. The N-terminal domains of E. glaucus 1St 1.4 and 1St1.1 are homologous to y-type subunits, whereas their C-terminal domains are similar to x-type subunits. Our results indicate that E. glaucus 1St 1.4 and 1St1.1 are novel HMW-GS variants or isoforms, and the characterization of both subunits can enhance our understanding on the structural differentiation and evolutionary relationship of HMW-GSs in Triticeae species.
Jiang
Qian-Tao
QT
Triticeae Research Institute, Sichuan Agricultural University, Ya'an, Sichuan, PR China.
Wei
Yu-Ming
YM
Lu
Zhen-Xiang
ZX
Pu
Zhi-En
ZE
Lan
Xiu-Jin
XJ
Zheng
You-Liang
YL
D000483:Alleles; D000595:Amino Acid Sequence; D005075:Biological Evolution; D018744:DNA, Plant / Q000235:genetics; D031749:Elymus / Q000235:genetics* / Q000254:growth & development; D014644:Genetic Variation; D005983:Glutens / Q000737:chemistry* / Q000145:classification / Q000235:genetics; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010802:Phylogeny; D021122:Protein Subunits; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
D018744:DNA, Plant; D021122:Protein Subunits; D005983:Glutens; C037302:glutenin