Figure 2.

Classification and diversity of PutAs. A, the three domain architectures of PutAs. B, phylogenetic tree based on global sequence alignments of PutAs. PutAs with architecture types A, B, and C are indicated by black, blue, and red type, respectively. The four PutAs for which crystal structures have been obtained are listed in large type. The alignments were calculated with Clustal Omega (56) and visualized with DrawTree (57). C, structures of PutA oligomers that have been validated by crystallography and SAXS (PDB codes 4NMA, 3HAZ, and 5KF6).