Evolution of a designed retro-aldolase leads to complete active site remodeling.

ABSTRACT: Evolutionary advances are often fueled by unanticipated innovation. Directed evolution of a computationally designed enzyme suggests that pronounced molecular changes can also drive the optimization of primitive protein active sites. The specific activity of an artificial retro-aldolase was boosted >4,400-fold by random mutagenesis and screening, affording catalytic efficiencies approaching those of natural enzymes. However, structural and mechanistic studies reveal that the engineered catalytic apparatus, consisting of a reactive lysine and an ordered water molecule, was unexpectedly abandoned in favor of a new lysine residue in a substrate-binding pocket created during the optimization process. Structures of the initial in silico design, a mechanistically promiscuous intermediate and one

SUBMITTER: Giger L 

PROVIDER: S-EPMC3720730 | biostudies-literature | 2013 Aug

REPOSITORIES: biostudies-literature