| Title: | Predicting the substrate specificity of a glycosyltransferase implicated in the production of phenolic volatiles in tomato fruit |
| Author(s): | Louveau T; Leitao C; Green S; Hamiaux C; van der Rest B; Dechy-Cabaret O; Atkinson RG; Chervin C; |
| Address: | "Universite de Toulouse, UMR Genomique et Biotechnologie des Fruits, INRA-INP/ENSAT, Castanet-Tolosan, France" |
| DOI: | 10.1111/j.1742-4658.2010.07962.x |
| ISSN/ISBN: | 1742-4658 (Electronic) 1742-464X (Linking) |
| Abstract: | "The volatile compounds that constitute the fruit aroma of ripe tomato (Solanum lycopersicum) are often sequestered in glycosylated form. A homology-based screen was used to identify the gene SlUGT5, which is a member of UDP-glycosyltransferase 72 family and shows specificity towards a range of substrates, including flavonoid, flavanols, hydroquinone, xenobiotics and chlorinated pollutants. SlUGT5 was shown to be expressed primarily in ripening fruit and flowers, and mapped to chromosome I in a region containing a QTL that affected the content of guaiacol and eugenol in tomato crosses. Recombinant SlUGT5 protein demonstrated significant activity towards guaiacol and eugenol, as well as benzyl alcohol and methyl salicylate; however, the highest in vitro activity and affinity was shown for hydroquinone and salicyl alcohol. NMR analysis identified isosalicin as the only product of salicyl alcohol glycosylation. Protein modelling and substrate docking analysis were used to assess the basis for the substrate specificity of SlUGT5. The analysis correctly predicted the interactions with SlUGT5 substrates, and also indicated that increased hydrogen bonding, due to the presence of a second hydrophilic group in methyl salicylate, guaiacol and hydroquinone, appeared to more favourably anchor these acceptors within the glycosylation site, leading to increased stability, higher activities and higher substrate affinities" |
| Keywords: | "Amino Acid Sequence Benzyl Alcohol/chemistry/metabolism Benzyl Alcohols/chemistry/metabolism Catalytic Domain/physiology Chromosomes/genetics Cloning, Molecular Escherichia coli/genetics/metabolism Eugenol/chemistry/metabolism Gene Expression/genetics Gly;" |
| Notes: | "MedlineLouveau, Thomas Leitao, Celine Green, Sol Hamiaux, Cyril van der Rest, Benoit Dechy-Cabaret, Odile Atkinson, Ross G Chervin, Christian eng Research Support, Non-U.S. Gov't England 2010/12/21 FEBS J. 2011 Jan; 278(2):390-400. doi: 10.1111/j.1742-4658.2010.07962.x. Epub 2010 Dec 17" |
