The use of abscisic acid analogues to analyse the substrate selectivity of UGT71B6, a UDP-glycosyltransferase of Arabidopsis thaliana.
This study analyses the activity of an Arabidopsis thaliana UDP-glycosyltransferase, UGT71B6 (71B6), towards abscisic acid (ABA) and its structural analogues. The enzyme preferentially glucosylated ABA and not its catabolites. The requirement for a specific chiral configuration of (+)-ABA was demonstrated through the use of analogues with the chiral centre changed or removed. The enzyme was able to accommodate extra bulk around the double bond of the ABA ring but not alterations to the 8'- and 9'-methyl groups. Interestingly, the ketone of ABA was not required for glucosylation. Bioactive analogues, resistant to 8'-hydroxylation, were also poor substrates for conjugation by UGT71B6. This suggests the compounds may be resistant to both pathways of ABA inactivation and may, therefore, prove to be useful agrochemicals for field applications.
Priest
David M
DM
CNAP, Department of Biology (Area 8), University of York, York YO10 5YW, United Kingdom.
Jackson
Rosamond G
RG
Ashford
David A
DA
Abrams
Suzanne R
SR
Bowles
Dianna J
DJ
D000040:Abscisic Acid / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D017360:Arabidopsis / Q000201:enzymology*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000378:metabolism*; D016695:Glycosyltransferases / Q000737:chemistry / Q000378:metabolism*; D013379:Substrate Specificity
D029681:Arabidopsis Proteins; D000040:Abscisic Acid; D016695:Glycosyltransferases; C503922:UGT71B6 protein, Arabidopsis