Alanine Amino Acid Substitution BIOORGANIC CHEMISTRY BIOQUIMICA CHEMISTRY, PHYSICAL ORGANIC Catalysis Catalytic Domain ENZIMAS ENZYMES Escherichia coli Isoleucine Kinetics MECANISMOS BIOORGANICOS Molecular Dynamics Simulation Mutation NADP QUIMICA BIOLOGICA QUIMICA BIOORGANICA QUIMICA ORGANICO FISICA Tetrahydrofolate Dehydrogenase Z3950.LOC.GOV:7090/VOYAGER alanine article biotransformation catalysis chemical reaction crystal structure dihydrofolate reductase hydrogen isoleucine