Analysis of Two New Arabinosyltransferases Belonging to the Carbohydrate-Active Enzyme (CAZY) Glycosyl Transferase Family1 Provides Insights into Disease Resistance and Sugar Donor Specificity

Thomas Louveau, Anastasia Orme, Hans Pfalzgraf, Michael J. Stephenson, Rachel Melton, Gerhard Saalbach, Andrew M. Hemmings, Aymeric Leveau, Martin Rejzek, Robert John Vickerstaff, Tim Langdon, Robert A. Field, Anne Osbourn

Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

48 Dyfyniadau (Scopus)
242 Wedi eu Llwytho i Lawr (Pure)

Crynodeb

Glycosylation of small molecules is critical for numerous biological processes in plants, including hormone homeostasis, neutralization of xenobiotics, and synthesis and storage of specialized metabolites. Glycosylation of plant natural products is usually performed by uridine diphosphate-dependent glycosyltransferases (UGTs). Triterpene glycosides (saponins) are a large family of plant natural products that determine important agronomic traits such as disease resistance and flavor and have numerous pharmaceutical applications. Most characterized plant natural product UGTs are glucosyltransferases, and little is known about enzymes that add other sugars. Here we report the discovery and characterization of AsAAT1 (UGT99D1), which is required for biosynthesis of the antifungal saponin avenacin A-1 in oat (Avena strigosa). This enzyme adds l-Ara to the triterpene scaffold at the C-3 position, a modification critical for disease resistance. The only previously reported plant natural product arabinosyltransferase is a flavonoid arabinosyltransferase from Arabidopsis (Arabidopsis thaliana). We show that AsAAT1 has high specificity for UDP-β-l-arabinopyranose, identify two amino acids required for sugar donor specificity, and through targeted mutagenesis convert AsAAT1 into a glucosyltransferase. We further identify a second arabinosyltransferase potentially implicated in the biosynthesis of saponins that determine bitterness in soybean (Glycine max). Our investigations suggest independent evolution of UDP-Ara sugar donor specificity in arabinosyltransferases in monocots and eudicots.
Iaith wreiddiolSaesneg
Tudalennau (o-i)3038-3057
Nifer y tudalennau20
CyfnodolynPlant Cell
Cyfrol30
Rhif cyhoeddi12
Dynodwyr Gwrthrych Digidol (DOIs)
StatwsCyhoeddwyd - 14 Tach 2018

Ôl bys

Gweld gwybodaeth am bynciau ymchwil 'Analysis of Two New Arabinosyltransferases Belonging to the Carbohydrate-Active Enzyme (CAZY) Glycosyl Transferase Family1 Provides Insights into Disease Resistance and Sugar Donor Specificity'. Gyda’i gilydd, maen nhw’n ffurfio ôl bys unigryw.

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