conparison of structure and substrate specificity of UDP-glucose:anthocyanidin 3-O-glucosyltransferase, Ct3GT-A, from Clitoria ternatea and flavonoid glycosyltransferase, VvGT1, from Vitis vinifera detailed overview
two wild-type plants and two independent mutants of Medicago truncatula with altered anthocyanin content in leaves are compared at metabolite profile, gene structure and enzyme transcript levels. Flavonoid profiles show conserved levels of dihydroflavonols, leucoanthocyanidins and flavonols, while anthocyanidin, anthocyanin and isoflavone levels are lower in the mutants (up to 90% less) compared with the wild-types, phenotypes, overview. The enzyme is downregulated in the mutants compared to wild-type
UDP-sugar biosynthetic pathway to cyanidin 3-galactoside biosynthesis, apple skin coloration with anthocyanin accumulation coincides with transcript levels for the enzyme
the structure of Ct3GT-A shows a common folding topology, the GT-B fold, comprised of two Rossmann-like beta/alpha/beta domains and a cleft located between the N- and C-domains containing two cavities that are used as binding sites for the donor (UDP-Glc) and acceptor substrates, structure-function relationship analysis, overview. The donor-binding site conserved as a UGT signature PSPG motif is located in the C-domain of Ct3GT-A, and the C-terminal helix comprising residues 431-445 participates in forming the N-domain after crossing the cleft. The acceptor-binding site is formed mostly by the residues from the N-domain. Besides the hydrophobic residues Phe12, Phe116, Trp135, Tyr145, Phe192 and Leu196, the hydrophilic residues Asn137, Asp181 and Asp367 are arranged to form the acceptor-binding site
the structure of Ct3GT-A shows a common folding topology, the GT-B fold, comprised of two Rossmann-like beta/alpha/beta domains and a cleft located between the N- and C-domains containing two cavities that are used as binding sites for the donor (UDP-Glc) and acceptor substrates, structure-function relationship analysis, overview. The donor-binding site conserved as a UGT signature PSPG motif is located in the C-domain of Ct3GT-A, and the C-terminal helix comprising residues 431-445 participates in forming the N-domain after crossing the cleft. The acceptor-binding site is formed mostly by the residues from the N-domain. Besides the hydrophobic residues Phe12, Phe116, Trp135, Tyr145, Phe192 and Leu196, the hydrophilic residues Asn137, Asp181 and Asp367 are arranged to form the acceptor-binding site