Figure 3

Reconstructed evolutionary history of β-grasp fold. Individual lineages are listed to the left of the figure grouped according to classifications given in the text, with their inferred evolutionary depth traced by solid horizontal lines across the relative temporal epochs representing major evolutionary transitional periods shown as vertical lines. The horizontal lines are color-coded according to their observed phyletic distributions, the key for this coloring scheme is given at the bottom of the figure. Dashed lines indicate uncertainty in terms of the origins of a lineage, while grey ellipses group lineages of relatively restricted phyletic distribution with more broadly distributed lineages, indicating that the former likely underwent rapid divergence from the latter. Major predicted structural/functional transitions of the fold are marked by green ellipses with a brief description given. Colored, labeled squares immediately to the left of the lineage names represent broad functional categories: E, enzymatic activity; LMB, ligand or metal-binding; CO, conjugated versions; AD, mediator of protein-protein interactions; RNA, RNA metabolism-related.