Unrooted phylogenetic tree of N - terminal NBDs of 103 ABC proteins of T . urticae. Amino acid sequences of NBDs were aligned using MUSCLE  and subjected to a maximum likelihood analysis using Treefinder . For amino acid alignment, amino acid substitution model and likelihood score of the constructed phylogenetic tree see Additional file 9 and Additional file 10. Numbers at important nodes represent the bootstrap values resulting from 1000 pseudoreplicates (LR-ELW). The scale bar represents 0.5 amino-acid substitutions per site. The different ABC protein subfamilies are indicated by shaded colors. T. urticae ABC protein sequences can be found in Additional file 12.