חיפוש מתקדם
Plant Journal
Carmi, N., Institute of Field and Garden Crops, ARO, Volcani Center, Bet Dagan 50250, Israel
Zhang, G., Institute of Field and Garden Crops, ARO, Volcani Center, Bet Dagan 50250, Israel
Petreikov, M., Institute of Field and Garden Crops, ARO, Volcani Center, Bet Dagan 50250, Israel
Gao, Z., Institute of Field and Garden Crops, ARO, Volcani Center, Bet Dagan 50250, Israel
Eyal, Y., Institute of Horticulture, ARO, Volcani Center, Bet Dagan 50250, Israel
Granot, D., Institute of Field and Garden Crops, ARO, Volcani Center, Bet Dagan 50250, Israel
Schaffer, A.A., Institute of Field and Garden Crops, ARO, Volcani Center, Bet Dagan 50250, Israel
Raffinose and stachyose are ubiquitous galactosyl-sucrose oligosaccharides in the plant kingdom which play major roles, second only to sucrose, in photoassimilate translocation and seed carbohydrate storage. These sugars are initially metabolised by α-galactosidases (α-gal). We report the cloning and functional expression of the first genes, CmAGA1 and CmAGA2, encoding for plant α-gals with alkaline pH optima from melon fruit (Cucumis melo L.), a raffinose and stachyose translocating species. The alkaline α-gal genes show very high sequence homology with a family of undefined 'seed imbibition proteins' (SIPs) which are present in a wide range of plant families. In order to confirm the function of SIP proteins, a representative SIP gene, from tomato, was expressed and shown to have alkaline α-gal activity. Phylogenetic analysis based on amino acid sequences shows that the family of alkaline α-gals shares little homology with the known prokaryotic and eukaryotic α-gals of glycosyl hydrolase families 27 and 36, with the exception of two cross-family conserved sequences containing aspartates which probably function in the catalytic step. This previously uncharacterised, plant-specific α-gal family of glycosyl hydrolases, with optimal activity at neutral-alkaline pH likely functions in key processes of galactosyl-oligosaccharide metabolism, such as during seed germination and translocation of RFO photosynthate.
פותח על ידי קלירמאש פתרונות בע"מ -
הספר "אוצר וולקני"
אודות
תנאי שימוש
Cloning and functional expression of alkaline α-galactosidase from melon fruit: Similarity to plant SIP proteins uncovers a novel family of plant glycosyl hydrolases
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Carmi, N., Institute of Field and Garden Crops, ARO, Volcani Center, Bet Dagan 50250, Israel
Zhang, G., Institute of Field and Garden Crops, ARO, Volcani Center, Bet Dagan 50250, Israel
Petreikov, M., Institute of Field and Garden Crops, ARO, Volcani Center, Bet Dagan 50250, Israel
Gao, Z., Institute of Field and Garden Crops, ARO, Volcani Center, Bet Dagan 50250, Israel
Eyal, Y., Institute of Horticulture, ARO, Volcani Center, Bet Dagan 50250, Israel
Granot, D., Institute of Field and Garden Crops, ARO, Volcani Center, Bet Dagan 50250, Israel
Schaffer, A.A., Institute of Field and Garden Crops, ARO, Volcani Center, Bet Dagan 50250, Israel
Cloning and functional expression of alkaline α-galactosidase from melon fruit: Similarity to plant SIP proteins uncovers a novel family of plant glycosyl hydrolases
Raffinose and stachyose are ubiquitous galactosyl-sucrose oligosaccharides in the plant kingdom which play major roles, second only to sucrose, in photoassimilate translocation and seed carbohydrate storage. These sugars are initially metabolised by α-galactosidases (α-gal). We report the cloning and functional expression of the first genes, CmAGA1 and CmAGA2, encoding for plant α-gals with alkaline pH optima from melon fruit (Cucumis melo L.), a raffinose and stachyose translocating species. The alkaline α-gal genes show very high sequence homology with a family of undefined 'seed imbibition proteins' (SIPs) which are present in a wide range of plant families. In order to confirm the function of SIP proteins, a representative SIP gene, from tomato, was expressed and shown to have alkaline α-gal activity. Phylogenetic analysis based on amino acid sequences shows that the family of alkaline α-gals shares little homology with the known prokaryotic and eukaryotic α-gals of glycosyl hydrolase families 27 and 36, with the exception of two cross-family conserved sequences containing aspartates which probably function in the catalytic step. This previously uncharacterised, plant-specific α-gal family of glycosyl hydrolases, with optimal activity at neutral-alkaline pH likely functions in key processes of galactosyl-oligosaccharide metabolism, such as during seed germination and translocation of RFO photosynthate.
Scientific Publication
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