IUBMB Enzyme Nomenclature

EC 2.4.1.239

Accepted name: flavonol-3-O-glucoside glucosyltransferase

Reaction: UDP-glucose + a flavonol 3-O-β-D-glucoside = UDP + a flavonol 3-O-β-D-glucosyl-(1→2)-β-D-glucoside

See diagram for reaction with 3-O-β-D-glucosides of kaempferol or quercetin.

Other name(s): UDP-glucose:flavonol-3-O-glucoside 2"-O-β-D-glucosyltransferase

Systematic name: UDP-glucose:flavonol-3-O-β-D-glucoside 2"-O-β-D-glucosyltransferase

Comments: One of three specific glucosyltransferases in pea (Pisum sativum) that successively add a β-D-glucosyl group first to O-3 of kaempferol, and then to O-2 of the previously added glucosyl group giving the 3-O-sophoroside and then the 3-O-sophorotrioside (see also EC 2.4.1.91, flavonol 3-O-glucosyltransferase and EC 2.4.1.240, flavonol-3-O-glycoside glucosyltransferase). TDP-glucose can replace UDP-glucose as the glucose donor but the reaction proceeds more slowly.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:

References:

1. Jourdan, P.S. and Mansell, R.L. Isolation and partial characterization of three glucosyl transferases involved in the biosynthesis of flavonol triglucosides in Pisum sativum L. Arch. Biochem. Biophys. 213 (1982) 434-443. [PMID: 6462109]

[EC 2.4.1.239 created 2004]


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