Faculty

Floyd Romesberg 
Associate Professor
Department of Chemistry
TSRI - 1998

Education 
B.S. The Ohio State University, 1988

Ph.D. Cornell University, 1994

Research Focus 
Biological and Biophysical Chemistry
My research interests are all related to understanding and evolving novel protein function. To this end, we are applying a wide variety of techniques, ranging from synthesis to phage display to femtosecond spectroscopy.

Protein Dynamics and Biomolecular Spectroscopy
We are developing the use of carbon-deuterium (C–D) bonds to visualize and characterize protein vibrations. We have shown that a single C–D bond may be visualized, and that the frequency and linewidth of the C–D absorption are sensitive to the local protein environment. In addition, we are able to characterize the global flexibility of a protein using three pulse photon echo spectroscopy. This technique is being applied to the study of the process of antibody somatic evolution, protein folding, and polymerase-mediated DNA synthesis, and is used to determine the contribution of protein dynamics and flexibility to biological function.

DNA Damage and Repair
Mutagenesis is not a random process, but rather, it results from biochemically regulated pathways that the cell induces under times of environmental stress. That cells play the central role in mutation of their own DNA is evidenced by experiments wherein deletion of certain genes causes no ill effect on cell growth, but renders the cells non-mutable in response to DNA damaging agents such as UV light. We are characterizing these inducible mutagenesis pathways in S. cerevisiae, using a combination of genetic and biochemical methods.

Expanding the Genetic Code
We are working to increase the information capacity of DNA by developing a third base pair, for eventual in vivo application in an unnatural organism that can build proteins with unnatural amino acids. In addition, we are using an activity-based, phage display selection system to optimize the polymerase enzymes that mediate DNA replication so that they accept the unnatural nucleobases as substrates.

Selected References 
D. Hanway, J. K. Chin, G. Xia, G. Oshiro, E. A. Winzler, F. E. Romesberg. New Genes in the UV- and MMS-Induced DNA Damage Response in Yeast. (2002) Proc. Natl. Acad. Sci. USA, 99, 10605-10610.

M. Fa, A. Radeghieri, A. A. Henry and F. E. Romesberg. Expanding the substrate repertoire of a DNA polymerase by directed evolution. (2004) J. Am. Chem. Soc., 126, 1748-1754.

R. Jimenez, J. Yin. T. Joo and F. E. Romesberg. Protein dynamics and the immunological evolution of molecular recognition. (2004) Proc. Natl. Acad. Sci. USA, 101, 3803-3808.

A. A. Henry, A. Goldbech Olsen, S. Matsuda, C. Yu., B. Geirstanger and F. E. Romesberg. Efforts to expand the genetic alphabet: identification of a stable and replicable unnatural DNA self pair. (2004) J. Am. Chem. Soc. 126(22):6923-31.