Functional comparison of the identified oligosaccharide SBPs of ABC transporters in B. lactis Bl-04. The phylogenetic tree was rooted by a characterized fructose-binding protein  as a functional and structural outlier group of oligosaccharide-binding proteins . Sub-clusters were defined by bootstrap values in percentages and the characterized SBP(s) identified within each sub-cluster, where the number of sequences are listed in brackets. The tree was colored by substrate specificity (maltose-binding proteins (green), cellodextrins (orange), GOS and lacto-N-biose (blue), XOS (light blue) and raffinose family oligosaccharides (red)) and sub-clusters were denoted by numbers as given in Table 4. The raffinose family oligosaccharide cluster was seemingly sub-clustering into two parts but with the current data could not be supported by boot-strap analysis.