Subsite-specific contributions of different aromatic residues in the active site architecture of glycoside hydrolase family 12.

ABSTRACT: The active site architecture of glycoside hydrolase (GH) is a contiguous subregion of the enzyme constituted by residues clustered in the three-dimensional space, recognizing the monomeric unit of ligand through hydrogen bonds and hydrophobic interactions. Mutations of the key residues in the active site architecture of the GH12 family exerted different impacts on catalytic efficiency. Binding affinities between the aromatic amino acids and carbohydrate rings were quantitatively determined by isothermal titration calorimetry (ITC) and the quantum mechanical (QM) method, showing that the binding capacity order of Tyr>Trp>His (and Phe) was determined by their side-chain properties. The results also revealed that the binding constant of a certain residue remained unchanged when altering its l

SUBMITTER: Zhang X 

PROVIDER: S-EPMC4680936 | biostudies-literature | 2015 Dec

REPOSITORIES: biostudies-literature