Kasia Walkiewicz, Ph. D.
GRADUATE STUDENT

Department of Biochemisty and Cell Biology

6100 Main St.

Houston, TX 77005
kw1@rice.edu
713-348-2492

Evolution of antibiotic resistance can occur through changes in the structure and function of the protein responsible for resistance. The mutational pathways accessible in protein evolution are limited to those which confer greater fitness to an organism. Studying biophysical origins of the mutational pathways can therefore provide a link between changes at the molecular level of proteins and the success of a strain within a population in the presence of antibiotic. 
The goal of my research is to study adaptation of B. fragilis (Tn4400) TetX and E. faecalis (Tn925)TetM proteins to tetracycline class of antibiotics. I use experimental evolution experiments to elucidate mutational pathways that alter the structure-function properties of TetX and TetM. To perform a structural analysis of the proteins with greater resistance, I work on high resolution structure determination of TetX and TetM using X-ray crystallography. 

PUBLICATIONS

Walkiewicz, K., Cardenas, A. S. B., Sun, C., Bacorn, C., Saxer, G., & Shamoo, Y. "Small changes in enzyme function can lead to surprisingly large fitness effects during adaptive evolution of antibiotic resistance." Proceedings of the National Academy of Sciences (2012).

Walkiewicz, K., Davlieva, M., Wu, G. and Shamoo, Y. (2011). Crystal structure ofBacteroides thetaiotaomicron TetX2, a tetracycline degrading monooxygenase at 2.8 Å resolution. PROTEINS: Structure, Function and Bioinformatics. in press


Yeo, H.J., Yokoyama, T., Walkiewicz, K., Kim, Y., Grass, S., Geme, J.W. 3rd. (2007) The structure of the Haemophilus influenzae HMW1 pro-piece reveals a structural domain essential for bacterial two-partner secretion. Journal of Biological Chemistry, 282(42):31076-84.