Fig 2. Phylogenetic tree of the U-box protein family from Medicago truncatula.

The 70-amino-acid U-box motifs from the 64 putative U-box proteins were aligned by CLUSTAL X 2.0, and the unrooted NJ phylogenetic tree was constructed by MEGA 5.1, using the p-distance method and a bootstrap value of 1,000. The six groups identified from the phylogenetic analysis are marked on the outside. The bar represents the branch length equivalent to 0.05 amino acid changes per residue. Table 1 provides additional information for the corresponding genes.