مرکز منطقه ای اطلاع رساني علوم و فناوري -

چكيده لاتين :

The aim of this research was to isolate and characterize the a-gliadin genes from T. turgidum ssp. paleocolchium. Nine genes were isolated from T. turgidum ssp. paleocolchicum (2n = 4x = 28, AABB) using the designed primers PF1 and PF2. The deduced protein sequences of the nine genes share the same typical polypeptide structures with known a-gliadin sequences. Among the nine a-gliadin genes, only Glil-7 and Gli 2-4 encoded putative mature proteins and the others were assumed to be pseudogenes due to their in-frame stop codon, which are attributed to the single base change C to T. Multi-alignment analysis indicated that the difference of the nine sequences mainly existed in the repetitive domain and the two polyglutamine regions. The repetitive domain could be considered as the array of 14 motifs based on the codon series CCA TT/AT CCA/G CAR, where CAR represents a 3-6 glutamine codon-rich region. Almost all codons in polyglutamine domains encode glutamine. However, 26 codons are not glutamine codons, which mainly resulted from single base changes. It is also found that the polyglutamine domain II is more variable than the polyglutamine domain I. Gli1-2 contained an extra cysteine, which was created by a serine-to-cysteine residue change at position 240, thus, it would have one free cysteine for intermolecular disulfide bond formation. Cluster analysis showed that sequences Gli1-10, Gli2-5 and Gli2-4 might be obtained from the genome A, whereas Gli2-2 and Gli1-9 from the genome B.