Associate Professor of Microbiology
Office Location: Health Sciences, J-167A
Campus Box: 357735
Beth Traxler received her Ph.D. in biology from Carnegie Mellon University where she studied the mechanism of DNA processing during bacterial conjugation. Her postdoctoral research on the assembly and structure of membrane proteins was done at Harvard Medical School in the laboratory of Dr. Jon Beckwith.
The research in Dr. Traxler's laboratory focuses on the genetic and biochemical analysis of protein folding and function. The lab uses two different models found in Gram negative bacteria. One interest is the characterization of ATP binding cassette (ABC) proteins in the Escherichia coli cytoplasmic membrane. This work focuses on the maltose (MalFGK) transporter as a model of the in vivo folding process for heteromeric membrane proteins complexes in general and for proteins of the ABC superfamily in particular. This analysis has led the lab to propose a novel model for the mechanism of membrane protein folding, in which a final complex can assemble in non-ordered process from a variety of intermediate complexes. In addition, the lab is characterizing the specificity of protein-protein interactions among the many ABC transporter subunits expressed in a bacterial cell. A second interest of the lab focuses on the processing of DNA and on membrane-based events during late stages of bacterial conjugation. Bacterial conjugation is an efficient way to transfer genetic information among prokaryotes and accounts for the dissemination of many antibiotic resistance determinants among pathogens. The analysis exploits the well-characterized F plasmid of E. coli as a model and aims to characterize the mechanism of DNA processing and DNA transfer through the cell envelope during conjugation.
Recently, the lab has been involved in the development of materials for nanotechnology. Different proteins characterized in the labís genetic analyses are being engineered by the addition of polypeptide sequences that bind to various inorganic compounds. Those inorganic compounds can be arranged in predictable structures, based on the self-assembly properties of the substrate proteins. Examples include using different DNA binding proteins to organize inorganic nanoparticles along a DNA guide.
Kennedy, K. A. and B. Traxler. 1999. MalK forms a dimer independent of its assembly into the MalFGK, ATP-binding cassette transporter of E. coli. J. Biological Chemistry 274: 6259-6264.
Lee, M.H., N. Kosuk, J. Bailey, B. Traxler, and Manoil, C. 1999. Analysis of F Factor TraD Membrane Topology by Use of Gene Fusion and Trypsin-Sensitive Insertions. J. Bacteriology 181: 6108-6113.
Kennedy, K.A., E.G Gachelet, and B. Traxler. 2004. Evidence for multiple pathways in the assembly of the E. coli maltose transport complex. J. Biological Chemistry, 279 : 33290-33297.
Sharma, S., J.A. Davis, T. Ayvaz, B. Traxler, and A.L. Davidson. 2005. Functional reassembly of the E. coli maltose transporter following purification of a MalF-MalG subassembly. J. Bacteriology, 187: 2908-2911.
Dai, H., W.S. Choe, C.K. Thai, M. Sarikaya, B.A. Traxler, F. Baneyx, and D.T. Schwartz. 2005. Nonequilibrium Synthesis and Assembly of Hybrid Inorganic-Protein Nanostructures Using an Engineered DNA Binding Protein. J. Amer. Chem. Soc., in press.