Functional characterisation of a putative rhamnogalacturonan II specific xylosyltransferase.
An Arabidopsis thaliana gene, At1g56550, was expressed in Pichia pastoris and the recombinant protein was shown to catalyse transfer of D-xylose from UDP-alpha-D-xylose onto methyl alpha-L-fucoside. The product formed was shown by 1D and 2D 1H NMR spectroscopy to be Me alpha-D-Xyl-(1,3)-alpha-L-Fuc, which is identical to the proposed target structure in the A-chain of rhamnogalacturonan II. Chemically synthesized methyl L-fucosides derivatized by methyl groups on either the 2-, 3- or 4 position were tested as acceptor substrates but only methyl 4-O-methyl-alpha-L-fucopyranoside acted as an acceptor, although to a lesser extent than methyl alpha-L-fucoside. At1g56550 is suggested to encode a rhamnogalacturonan II specific xylosyltransferase.
Egelund
Jack
J
Institute of Genetics and Biotechnology, Faculty of Agricultural Sciences, University of Aarhus, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark.
Damager
Iben
I
Faber
Kirsten
K
Olsen
Carl-Erik
CE
Ulvskov
Peter
P
Petersen
Bent Larsen
BL