Structure and catalysis in the Escherichia coli hotdog-fold thioesterase paralogs YdiI and YbdB.

ABSTRACT: Herein, the structural determinants for substrate recognition and catalysis in two hotdog-fold thioesterase paralogs, YbdB and YdiI from Escherichia coli, are identified and analyzed to provide insight into the evolution of biological function in the hotdog-fold enzyme superfamily. The X-ray crystal structures of YbdB and YdiI, in complex with inert substrate analogs, determined in this study revealed the locations of the respective thioester substrate binding sites and the identity of the residues positioned for substrate binding and catalysis. The importance of each of these residues was assessed through amino acid replacements followed by steady-state kinetic analyses of the corresponding site-directed mutants. Transient kinetic and solvent (18)O-labeling studies were then carried out t

SUBMITTER: Wu R 

PROVIDER: S-EPMC4116151 | biostudies-literature | 2014 Jul

REPOSITORIES: biostudies-literature