Fig. 2

Phylogenetic analysis of putative bacterial avidins. a Phylogeny tree of the putative bacterial avidins. The verified avidins are shown with bold red font. The avidins with resolved 3D structure are indicated with black star symbol. The avidins containing predicted secretion signal peptide are indicated by cyan spheres. The avidins containing C-terminal extension are indicated by purple plus sign. The avidins containing predicted protease domain fusion are indicated by blue P letter. The bacterial avidins are grouped into 11 branches indicated with colors. b Phylogenetic cladogram tree of functionally verified avidins, colored according to a. c Phylogenetic cladogram tree of the verified and putative bacterial avidin sequences with collapsed subgroups. Triangle marks the collapsed clade, red text the clades containing verified avidins, and grey text that the indicated sequence was an outlier. The two outlier species, Aminiphilus circumscriptus and Rhodonobacter sp. OR444, were isolated from waste sludge and heavy metal polluted soil respectively