Mechanism of Nucleotidyltransfer Reaction and Role of Mg2+ Ion in Sugar Nucleotidyltransferases

Sugar nucleotidyl transferases (SNTs) catalyze nucleotidyltransfer reactions to form sugar-nucleotides and pyrophosphate in the presence of two Mg2+ ions (Mg2+A and Mg2+B). We unveil the mechanism and free energetics of nucleotidyl transfer reaction in an SNT called GlmU through hybrid quantum mechanics-molecular mechanics molecular dynamics simulations and free energy calculations. The study identifies the roles of the active site residues and...