Faculty

Our goal is to understand the mechanisms used by biological catalysts, both proteins and nucleic acids, to achieve high efficiency, stringent specificity and rigorous control. We are elucidating catalytic mechanisms, essential active site features, specificity and inhibition of metalloenzymes and ribozymes, including protein farnesyltransferase, UDP-3-O-acyl-GlcNAC deacetylase, histone deacetylase and ribonuclease P. These studies should enhance the design of potent inhibitors of these enzymes useful for the treatment of cancer or bacterial infections. In particular, we are investigating the role of proteins in modulating the reactivity of bound Zn(II) or Fe(II) and developing specific inhibitors that coordinate the active site metal. We are also investigating the molecular recognition of substrates leading to the in vivo specificity of protein prenylation and acetylation using peptide and small molecule libraries. Finally, we are elucidating the role of metal ions and protein/RNA interactions in ribonuclease P, a ribozyme/protein complex using a variety of biophysical techniques, including NMR and time-resolved fluorescence. These studies are increasing our understanding of the catalytic modes used by ribozymes in comparison to protein catalysts.

We are testing our understanding of biological catalysis by the rational design or redesign of an enzyme. To this end, we are redesigning the zinc metalloenzyme, carbonic anhydrase II, to optimize a fluorescent biosensor for measuring and imaging metal ions in complex biological mixtures. Zinc and copper ions are proposed to play important biological roles, especially in neurobiology, which can investigated using novel imaging methods. Additionally, we are using "directed evolution" approaches to prepare and identify aldolase variants with novel substrate specificities. These aldolase variants will be used to improve the utility of these enzymes as biocatalysts for organic synthetic reactions. Characterization of the structure and function of these novel proteins will provide insights into catalysis, molecular recognition and molecular evolution.

Awards

Fellow of the American Association for the Advancement of Science
Chair-elect; Biological Chemistry Division, American Chemical Society
Chair; Enzymes, Coenzymes and Metabolic Pathways Gordon Conference
American Heart Association Established Investigator Award
David and Lucile Packard Foundation Fellowship
American Cancer Society Junior Faculty Research Award
National Institutes of Health Postdoctoral Fellow

Representative Publications

1. Hartman, H.L., Hicks, K.A. and Fierke, C.A., "Peptide Specificity of Protein Prenyltransferases is Determined Mainly by Reactivity Rather than Binding Affinity", Biochem., 2005, in press.

2. Rueda, D., Hsieh, J., Day-Storms, J.J. and Fierke, C.A., "The 5' Leader of Precursor tRNA^Asp Bound to the Bacillus subtilis RNase P Holoenzyme Has an Extended Conformation", Biochem., 2005, in press.

3. Hernick, M., Gennadios, H.A., Whittington, D.A., Rusche, K.M., Christianson, D.W. and Fierke, C.A., "UDP-3-O-(R-3-Hydroxymyristoyl)-N-Acetylglucosamine Deactylase Functions Through a General Acid-Base Catalyst Pair Mechanism:, J. Biol. Chem., 2005, 280, 16969.

4. Griffiths, J.S., Chariyan, M., Corbell, J.B., Pocivavsek, L., Fierke, C.A. and Toone, E., "A Bacterial Selection for the Directed Evolution of 2-Keto-3-deoxy-6-phosphogluconate aldolases", Bioorg. Med. Chem., 2004, 12, 4067.

5. Day-Storms, J.J., Niranjanakumari, S. and Fierke, C.A., "Ionic Interactions between PRNA and P Protein in Bacillus subtilis RNase P Characterized using a Magnetocapture-Based Assay", RNA, 2004, 10, 1595.

6. Whittington, D.A., Rusche, K.M., Shin, H., Fierke, C.A. and Christianson, D.W., "Crystal structure of LpxC, a zinc-dependent deacetylase essential for endotoxin biosynthesis", Proc. Natl. Acad. Sci. U.S.A., 2003, 100, 8146.

7. Pirrung, M.C., Tumey, L.N., Raetz, C.R.H., Jackman, J.E., Snehalatha, K., McClerren, A.L., Fierke, C.A., Gantt, S.L. and Rusche, K., "Inhibition of the Antibacterial Target UDP-(3-Oacyl)-N-acetlyglucosamine Deacetylase (LpxC). Isoxazoline Zinc Amidase Inhibitors Bearing Diverse Metal Binding Groups", J. Med. Chem., 2002, 45, 4359.