My laboratory uses genetic and biochemical approaches to examine the mechanism by which the cytoplasmic membrane ion electrochemical potential is harnessed to energize the biogenesis and maintenance of the essentially non-energized outer membrane of Gram negative bacteria. Because the outer membrane is the principle interface between the organism and the environment, these studies impact a broad set of biological issues; ranging from ecology to pathogenesis (although the molecular biology and energetics are alone more than sufficient to keep us all very busy).
Gresock, M. G., M. I. Savenkova, R. A. Larsen, A. A. Ollis, and K. Postle. 2011. Death of the TonB shuttle hypothesis. Front. Microbiol. 2: 1-8.
Brinkman, K.K., and R.A. Larsen. 2008. Interactions of the energy transducer TonB with noncognate energy-harvesting complexes. J. Bacteriol. 190: 421-427.
Weitzel, A.C., and R.A. Larsen. 2008. Differential complementation of ∆toA Escherichia coli by a Yersinia enterocolitica TolA homologue. FEMS Micro Lett 282: 81-88.
Keller, K. L., K. K. Brinkman, and R. A. Larsen. 2007. TonB/TolA amino-terminal domain modeling. Methods in Enzymology 423:134-148.
Larsen, R.A., G.E. Deckert, K.A. Kastead, S. Devanathan, K. L. Keller, and K. Postle. 2007. His20 provides the sole functionally significant side chain in the essential TonB transmembrane domain. J. Bacteriol. 189:2825-2833.
Postle, K., and Larsen, R. A. 2007. TonB-dependent energy transduction between outer and cytoplasmic membranes. BioMetals. 20:453-465.
Postle, K., and R.A. Larsen. 2005. The TonB, Ex6B, and ExbD proteins. In: Iron Tansport in Bacteria. Crosa, J.H., Mey, A.R., Payne, S.M. (eds). ASM Press, Washington. pp. 96-112.
Larsen, R.A., Chen, G.J., Postle, K. 2003. Performance of standard phenotypic assays for TonB activity, as evaluated by varying the relative levels of functional, wild-type TonB. J. Bacteriol. 185:4699-4706.
Larsen, R.A., Letain, T.E., Postle, K. 2003. In vivo evidence of TonB shuttling between the cytoplasmic and outer membranes of Escherichia coli. Mol. Microbiol., 49:211-218.
Higgs, P.I., Larsen, R.A., Postle, K. 2002. Per cell quantitation of the known components of the Escherichia coli TonB energy transduction system: TonB, ExbB, ExbD, and an outer membrane protein, FepA. Mol. Microbiol. 44:271-281.
Larsen, R.A., Postle, K. 2001. Conserved residues S16 and H20, and their relative positioning, are essential for TonB activity, cross-linking of TonB with ExbB, and the ability of TonB to respond to proton motive force. J. Biol. Chem. 276:8111-8117.