Figure 1.

Phylogenetic tree of the GT47 family members of Arabidopsis. The alignment was generated using ClustalX, and the branching pattern was visualized by TreeView. Squares, Gene products predicted to be cytoplasmic by both the SignalP-HMM and Transmembrane Hidden Markov model (TMHMM) algorithms; circles, gene products predicted to have a cleaved signal peptide. All other putative proteins are likely to contain at least one transmembrane domain. AtGUT1 and AtGUT2 are close homologs to the putative RG-II glucuronosyltransferase from Nicotiana plumbaginifolia (Iwai et al., 2002), and EXT1 denotes the glucuronosyltransferase domain of exostosin 1 from humans (Homo sapiens). Proteins with known (EXT1 and MUR3) or predicted functions (At-GUT1 and AtGUT2) are boxed.