Substrate specificity and sequence analysis define a polyphyletic origin of betanidin 5- and 6-O-glucosyltransferase from Dorotheanthus bellidiformis.
Betanidin 6-O-glucosyltransferase (6-GT) is involved in the glycosylation of betacyanins, which replace the chromogenic anthocyanins as flower colorants in the Caryophyllales. The 6-GT cDNA was cloned from a cDNA library of Dorotheanthus bellidiformis (Burm. f.) N.E. Br., and the amino acid and nucleotide sequences were shown to be distinctly different from the corresponding betanidin 5-O-glucosyltransferase (5-GT) from the same plant species. Although both enzymes share very similar substrates, the proteins show only 19% amino acid sequence identity. In contrast, the protein sequence of the 6-GT showed significant identity to GTs from other species and may identify a new cluster of putative anthocyanidin GTs. Therefore, 6-GT and 5-GT apparently have evolved independently from ancestral glucosyltransferases involved in flavonoid biosynthesis.
Vogt
Thomas
T
Leibniz-Institut für Pflanzenbiochemie, Halle/Saale. tvogt@ipb-halle.de
D000872:Anthocyanins / Q000378:metabolism; D001578:Benzopyrans / Q000378:metabolism; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D019143:Evolution, Molecular; D005419:Flavonoids / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D005964:Glucosyltransferases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D006031:Glycosylation; D019684:Magnoliopsida / Q000201:enzymology / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D011794:Quercetin / Q000378:metabolism; D017422:Sequence Analysis, DNA; D020539:Sequence Analysis, Protein; D013379:Substrate Specificity
D000872:Anthocyanins; D001578:Benzopyrans; D018076:DNA, Complementary; D005419:Flavonoids; C017154:cyanidin; D011794:Quercetin; D005964:Glucosyltransferases; C110839:betanidin 5-O-glucosyltransferase; C110840:betanidin 6-O-glucosyltransferase