Elizabeth E. Howell

Intact protein analysis for site-directed mutagenesis overexpression products: plasmid-encoded R67 dihydrofolate reductase.

Breaking symmetry: mutations engineered into R67 dihydrofolate reductase, a D2 symmetric homotetramer possessing a single active site pore.

Role of ionic interactions in ligand binding and catalysis of R67 dihydrofolate reductase.

NMR studies of the interaction of a type II dihydrofolate reductase with pyridine nucleotides reveal unexpected phosphatase and reductase activity.

Defining the binding site of homotetrameric R67 dihydrofolate reductase and correlating binding enthalpy with catalysis.

Role of Lys-32 residues in R67 dihydrofolate reductase probed by asymmetric mutations.

"Catch 222," the effects of symmetry on ligand binding and catalysis in R67 dihydrofolate reductase as determined by mutations at Tyr-69.

Searching sequence space: two different approaches to dihydrofolate reductase catalysis.

Preliminary neutron diffraction studies of Escherichia coli dihydrofolate reductase bound to the anticancer drug methotrexate.

Calorimetric studies of ligand binding in R67 dihydrofolate reductase.

Effects of temperature and viscosity on R67 dihydrofolate reductase catalysis.

Neutron diffraction studies of Escherichia coli dihydrofolate reductase complexed with methotrexate.

A preference for edgewise interactions between aromatic rings and carboxylate anions: the biological relevance of anion-quadrupole interactions.

Crystal structure of a type II dihydrofolate reductase catalytic ternary complex.

R67, the other dihydrofolate reductase: rational design of an alternate active site configuration.

A balancing act between net uptake of water during dihydrofolate binding and net release of water upon NADPH binding in R67 dihydrofolate reductase.

Tuning of the H-transfer coordinate in primitive versus well-evolved enzymes.

The effect of electrostatic shielding on H tunneling in R67 dihydrofolate reductase.

Radical redesign of a tandem array of four R67 dihydrofolate reductase genes yields a functional, folded protein possessing 45 substitutions.

The tail wagging the dog: insights into catalysis in R67 dihydrofolate reductase.

A survey of aspartate-phenylalanine and glutamate-phenylalanine interactions in the protein data bank: searching for anion-Ï€ pairs.

Thermodynamics and solvent effects on substrate and cofactor binding in Escherichia coli chromosomal dihydrofolate reductase.