Research and Teaching Interests
Our research is focused on elucidating the structure and function of proteins, with particular emphasis on fluorescent proteins and remodeling enzymes. The ultimate goal is to introduce novel biochemical, optical, or functional features into a protein's scaffold. We utilize macromolecular X-ray crystallography to determine atomic-resolution structures, steady-state spectroscopy to investigate protein maturation kinetics, ultra-fast spectroscopy to examine the photochemistry of intrinsic chromophores, and molecular biology for protein engineering purposes.
Protein self-processing reactions: In fluorescent proteins such as GFP, the biosynthesis of several chemically distinct chromophores involves self-catalysis of peptide cyclization and oxidation reactions. Our research aims to develop step-by-step mechanistic models for the amino acid derivatizations that occur spontaneously upon protein folding, yielding brightly colored fluorophores from a single gene product.
Structural basis of color evolution in fluorescent proteins: Four color classes (cyan, green, yellow, red) have evolved repeatedly and independently along different lineages of GFP-like proteins. We aim to understand how conformational remodeling facilitates phenotypic changes such as color switching events during protein evolution.
Bioenergy and photosynthesis: The regulation of carbon fixation in higher plants and green algae includes remodeling enzymes responsible for maintaining the activity of RuBisCo, which catalyzes the central carboxylation reaction. We are interested in determining the mechanism of action of these auxiliary factors, as they appear to limit the net rate of CO2 fixation at elevated temperatures.
Biomedical: We are investigating the structural and biochemical properties of M. tuberculosis protein factors with proposed roles in the regulation of MTB virulence.
"Biophysical Characterization of Higher Plant Rubisco Activase," Henderson, J. N., Hazra, S., Dunkle, A. M., Salvucci, M. E., Wachter*, R. M., Biophys. Biochim. Acta 1834 87-97 (2013)
"The 1.6 A structure of a FRET-optimized Cerulean Fluorescent Protein," Watkins, J. L., Kim, H., Markwardt, M. L., Chen, L., Fromme, R., Rizzo, M. A., Wachter*, R. M., Acta Crystallogr. D 69 767-773 (2013)
"Ultrafast Proton Shuttling in Psammocora Cyan Fluorescent Protein," Kennis, J. T. M., van Stokkum, I. H. M., Peterson, D. S., Pandit, A., Wachter, R. M., The Journal of Physical Chemistry B 117 11134-11143 (2013)
"Activation of Interspecies-hybrid Rubisco Enzymes to Assess Different Models for the Rubisco – Rubisco Activase Interaction ," Wachter, R. M., Salvucci, M. E., Carmo-Silva, A. E., Barta, C., Genkhov, T., Spreitzer, R. J., Photosynthesis Research DOI 10.1007/s11120-013-9827-0 (2013)
"Acid-Base Catalysis and Crystal Structures of a Least-Evolved Ancestral GFP-like Protein Undergoing Green-to-Red Photoconversion ," Kim, H., Grunkemeyer, T. J., Modi, C., Chen, L., Fromme, R., Matz, M. V., Wachter*, R. M., Biochemistry (in press) (2013)