Reaction: UDP-β-L-rhamnose + a flavonol 3-O-β-D-glucoside = UDP + a flavonol 3-O-[α-L-rhamnosyl-(1→6)-β-D-glucoside]
For diagram of reaction click here.
Glossary: UDP-β-L-rhamnose = UDP-6-deoxy-β-L-mannose
Other name(s): uridine diphosphorhamnose-flavonol 3-O-glucoside rhamnosyltransferase; UDP-rhamnose:flavonol 3-O-glucoside rhamnosyltransferase; UDP-L-rhamnose:flavonol-3-O-D-glucoside 6''-O-L-rhamnosyltransferase
Systematic name: UDP-β-L-rhamnose:flavonol-3-O-β-D-glucoside 6''-O-L-rhamnosyltransferase (configuration-inverting)
Comments: A configuration-inverting rhamnosyltransferase that converts flavonol 3-O-glucosides to 3-O-rutinosides. Also acts, more slowly, on rutin, quercetin 3-O-galactoside and flavonol 3-O-rhamnosides.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 83380-89-6
References:
1. Kleinehollenhorst, G., Behrens, H., Pegels, G., Srunk, N. and Wiermann, R. Formation of flavonol 3-O-diglycosides and flavonol 3-O-triglycosides by enzyme extracts from anthers of Tulipa cv apeldoorn - characterization and activity of 3 different O-glycosyltransferases during anther development. Z. Natursforsch. C: Biosci. 37 (1982) 587-599.
2. Jones, P., Messner, B., Nakajima, J., Schaffner, A.R. and Saito, K. UGT73C6 and UGT78D1, glycosyltransferases involved in flavonol glycoside biosynthesis in Arabidopsis thaliana. J. Biol. Chem. 278 (2003) 43910-43918. [PMID: 12900416]