Research Program Summary

My research focuses on developing innovative methodologies to study complex biological machinery. In particular, I am interested in using a combination of structural and functional tools to understand how signaling pathways influence human development and disease. Cryo-Electron Microscopy (EM) is an ideal technique to visualize macromolecular assemblies, such as ribosomes, at sub-nanometer resolution. Still, a major obstacle in the field is that many active cellular complexes are too labile or in too low abundance for conventional purification schemes. To address this issue, we developed the monolayer purification method and the functionalized Affinity Grid, that make it possible to rapidly purify complexes from crude cell lysates directly onto an EM Grid. These novel techniques provide a powerful approach for gathering structural information and allow us to view biological processes in a completely new fashion. We are now applying this technology to examine signaling complexes that regulate stem cell development in both normal and cancerous tissues. The knowledge gained from this line of research will shed light on the early events of stem cell commitment and cancer formation.

Education and Training

• Florida State University: Ph.D., Molecular Biophysics
• Old Dominion University: M.S., Chemistry
• Old Dominion University: B.S., Biochemistry

Previous Positions

• Harvard Medical School Postdoctoral Fellow

Selected Publications

• Kelly, D.F., Dukovski, D. and Walz, T.. (2010). A Practical Guide to the Use of Monolayer Purification and Affinity Grids. Methods in Enzymology, 481:83-107.
• Kelly, D.F., Lake, R.J., Middlekoop, T.C., Fan, H-Y., Artavanis-Tsakonas, S. and Walz, T.. (2010). Molecular Structure and Dimeric Organization of the Notch Extracellular Domain as Revealed by Electron Microscopy. PLoS ONE, 5:e10532.
• Kelly, D.F., Dukovski, D. and Walz, T.. (2008). Monolayer purification: a rapid method for isolating protein complexes for single-particle Electron Microscopy. PNAS, 150:4703-4708.
• Kelly, D.F., Abeyrathne, P.D., Dukovski, D. and Walz, T.. (2008). The Affiinity-Grid: a pre-fabricated EM grid for monolayer purification. J. Mol. Biol., 382(2):423-433.
• Kelly, D.F., Lake, R.J., Walz, T. and Artavanis-Tsakonas, S.. (2007). Conformational variability of the intracellular domain of Drosophila Notch and its interaction with Suppressor of Hairless. PNAS, 104:9591-9596.