The most striking example of this is the most distinct cluster found in the dendrogram which is separation that occurs at a height of ~4 (Figure ) and is made up of 5 β-lactamases. These 5 βlactamases contain 3 of the 6 phyla present throughout the whole dataset (Figure ). We applied the same approach as described for Figure to identify which contacts differed between the two groups, which by and large showed hydrogen bonds distributed throughout most of the protein to differ (Figure ). Finally, we note that an alternative strategy could be to first construct a phylogenetic tree/dendrogram using sequence data (which would contain many more examples), but then interpret a branch point of interest in the phylogenetic tree using the approach we described above based on available crystal structures and/or protein structure prediction.