Kathleen Postle
Professor of Biochemistry and Molecular Biology
301 Althouse LaboratoryUniversity Park, PA 16802
Research Interests
Signal transduction and iron transport in bacteria
Research Summary
Signal Transduction and Iron Transport in Bacteria
Gram negative bacteria are surrounded by a double concentric membrane system--the cytoplasmic, or inner, membrane and the outer membrane. Dr. Postle’s lab is studying a form of signal transduction in Escherichia coli: the means by which cytoplasmic membrane energy (protonmotive force) is transduced to transport proteins in the outer membrane by TonB protein. Current information indicates that energy is transduced by a series of conformational changes in cytoplasmic membrane TonB protein which are transmitted to the outer membrane transport proteins by direct physical contact. An understanding of the molecular mechanism of TonB-dependent energy transduction will provide unique insights into all signal transduction processes. Furthermore, the ability of many bacterial pathogens to obtain iron from host proteins like transferrin is a TonB-dependent process. Since pathogens lacking TonB can be compromised in their ability to cause disease, our understanding of the mechanism of TonB-dependent energy transduction can lead to the development of novel chemotherapeutics.
Representative Publications
- Larsen, R.A., Deckert, G.E., Keller, K., Devanathan, S., Kastead, K.A., and K. Postle (2007) Histidine 20 is the sole amino acid required for activity in the putative TonB transmembrane domain. J. Bacteriol. 189:2825-33.
- Vakharia, H., Kastead, K.A., and K. Postle (2007) Deletion and substitution analysis of the TonB Q160 region. J. Bacteriol. 189:4662-70.
- Devanathan, S. and K. Postle (2007) Studies on colicin B translocation: FepA is gated by TonB. Mol Microbiol. 65:441-53.
- Ollis, A.A., Manning, M., Held, K.G., and K. Postle (2009) Cytoplasmic membrane protonmotive force energizes periplasmic interactions between ExbD and TonB. Mol. Microbiol. 73:466.
- Postle, K., Kastead, K.A., Gresock, M.G., Ghosh, J., and C.D. Swayne (2010). The TonB dimeric crystal structures do not exist in vivo. mBio 1(5). pii:e00307-10.
- Swayne C. and K. Postle (2011) Taking the TonB transmembrane domain offline? Non-protonatable Asn substitutes fully for TonB His20. J Bacteriol. 193:3693-701.
- Jana B., Manning M., and K. Postle (2011) Mutations in the ExbB Cytoplasmic Carboxy Terminus Prevent Energy-dependent Interaction Between the TonB and ExbD Periplasmic Domains. J. Bacteriol. [Epub ahead of print]
- Gresock, M., Savenkova, M., Larsen, R.A., Ollis, A., and K. Postle (2011) Death of the TonB shuttle hypothesis. (2011) Frontiers in Microbial Physiology.
Search the Search the MEDLINE database at PubMed for articles by K. Postle
