The TIM barrel fold is highly evolvable, encompassing many superfamilies that accommodate a variety of functions; it has 875 unique EC numbers shared between 16 distinct superfamilies. However, among the superfamilies that comprise the TIM barrel fold, there is an unequal distribution of unique EC numbers. For instance, while the class I aldolase superfamily alone accounts for 325 unique EC numbers, the malate synthase superfamily only has six. Here, we examine the effect of active site composition on the evolvability of TIM barrel superfamilies by observing the proportion of active site residues residing outside of the conserved β-barrel characteristic of this fold. Our results indicate a threshold proportion of free active site residues, beyond which high evolvability appears. When considering factors contributing to TIM barrel evolvability, the contribution of the β-barrel to the active site may be key in determining if a superfamily is highly evolvable.

Evolvability vs. barrel contribution to the active site in TIM barrel fold superfamilies

255th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.