Sean Crosson


  • Associate Professor, Department of Biochemistry and Molecular Biology, Committee on Microbiology


Ph.D., The University of Chicago, 2002

B.A., Earlham College, 1996


The University of Chicago
929 East 57th Street
Chicago, Illinois 60637

Phone:  (773) 834-1926

Lab:       (773) 702-0439



An Integrative Analysis of Bacterial Signalling Systems

Cells have the extraordinary ability to rapidly modulate their physiology in response to changes in their environment. This plasticity is particularly evident in microbial species, many of which adapt to grow across an extremely diverse range of conditions. Our interests center on how chemical and physical signals are received, processed, and integrated by a bacterial cell to generate an adaptive response. To address these questions, we are using an interdisciplinary set of tools including NMR and crystallography to explore the structural basis of signal detection and transduction by sensor histidine kinases, genetics and array-based transcriptional profiling to decipher the function and topology of microbial signaling networks, and mathematical modeling to test our experimentally-derived network topologies.


Fiebig, A., Herrou, J., Fumeaux, C., Radhakrishnan, S.K., Viollier, P.H., and Crosson, S. 2014. A cell cycle and nutritional checkpoint controlling bacterial surface adhesion.PLoS Genetics: e1004101. doi: 10.1371/journal.pgen.1004101.

Herrou, J. and Crosson, S. 2013. Molecular structure of the Brucella abortus metalloprotein RicA, a Rab2-binding virulence effector. Biochemistry 52: 9020-9028.

Henry, J.T. and Crosson, S. 2013. Chromosome replication and segregation govern the biogenesis and inheritance of inorganic polyphosphate granules. Mol. Biol. Cell 24: 3177-3186.

Kim, H.-S., Caswell, C.C., Foreman, R., Roop, R.M., and Crosson, S. 2013. The Brucella abortus general stress response system regulates chronic mammalian infection and is controlled by phosphorylation and proteolysis. J. Biol. Chem. 288: 13906-13916.

Herrou, J. and Crosson, S. 2013. myo-inositol and D-ribose ligand discrimination in an ABC periplasmic binding protein. J. Bacteriol. 195: 2379-2388.

Boutte, C.C. and Crosson, S. 2013. Bacterial lifestyle shapes stringent response activation. Trends Microbiol. 21: 174-180.

Lin, Y., Li, Y., Crosson, S., Dinner, A.R., and Scherer, N.F. 2012. Phase resetting reveals network dynamics underlying a bacterial cell cycle. PLoS Comput. Biol. 8: e1002778. doi: 10.1371/journal.pcbi.1002778.

Herrou, J., Rotskoff, G., Luo, Y., Roux, B., and Crosson, S.  2012.  The structural basis of a protein partner switch that regulates the general stress response of α-proteobacteria. Proc. Natl. Acad. Sci. USA 109: E1415-1423.

Foreman, R., Fiebig, A., and Crosson, S. 2012.  The LovK-LovR two-component system is a regulator of the general stress pathway in Caulobacter crescentusJ. Bacteriol. 194: 3038-3049.

Heaton, B., Herrou, J., Blackwell, A.E., Wysocki, V.H., and Crosson, S.  2012.  Molecular structure and function of the novel BrnT/BrnA toxin-antitoxin system of Brucella abortus. J. Biol. Chem. 287:12098-12110.

Boutte, C.C., Henry, J.T., and Crosson, S.  2012.  ppGpp and polyphosphate modulate cell cycle progression in Caulobacter crescentus. J. Bacteriol. 194: 28-35.

Boutte, C.C. and Crosson, S.  2011.  The complex logic of stringent response regulation in Caulobacter crescentus: starvation signaling in an oligotrophic environment. Mol. Microbiol. 80: 695-714.

Herrou, J. and Crosson, S. 2011.  Function, structure, and mechanism in bacterial photosensory LOV proteins.  Nature Rev. Microbiol. 9: 713-723.

Henry, J.T. and Crosson, S.  2011.  Ligand binding PAS domains in a genomic, cellular, and structural context.  Annu. Rev. Microbiol. 65: 261-286.

van Stokkum I.H., Gauden M., Crosson S., Van Grondelle, R., Moffat, K., and Kennis, J.T.  2011.  The primary photophysics of the Avena sativa phototropin 1 LOV2 domain observed with time-resolved emission spectroscopy. Photochem. Photobiol. 87: 534-541.

Lin, Y., Crosson, S. and Scherer, N.F.  2010.  Single-gene tuning of Caulobacter cell cycle period and noise, swarming motility, and surface adhesion. Mol. Syst. Biol. 6: 445. doi:10.1038/msb.2010.95.

Purcell, E.B., McDonald, C.A., Palfey, B.A., and Crosson, S.  2010.  An analysis of solution structure and signaling mechanism of LovK, a sensor histidine kinase integrating light and redox signals.  Biochemistry 49: 6761-6770.

Herrou, J., Foreman, R., Fiebig, A., and Crosson, S.  2010. A structural model of anti-antisigma inhibition by a two-component receiver domain: the PhyR stress response regulator.  Mol. Microbiol. 78: 290-304.

Marks, M.E., Castro-Rojas, C.M., Teiling, C., Du, L., Kapatral, V. Walunas, T. and Crosson, S.  2010. The genetic basis of laboratory adaptation in Caulobacter crescentus. J. Bacteriol. 192: 3678-3688.

Fiebig, A. Castro-Rojas, C.M., Siegal-Gaskins, D., and Crosson, S.  2010. Interaction specificity, toxicity, and regulation of a paralogous set of ParE/RelE-family toxin-antitoxin systems.  Mol. Microbiol. 77: 236-251.

Alexandre, M., Purcell, E.B, Van Grondelle, R., Robert, B., Kennis, J., and Crosson, S.  2010. Electronic and protein structural dynamics of a photosensory LOV histidine kinase.  Biochemistry 49: 4752-4759.

Dalton, K.M. and Crosson, S.  2010.  A conserved mode of protein recognition and binding in a ParD-ParE toxin-antitoxin complex.  Biochemistry 49: 2205-2215.

Siegal-Gaskins, D., Ash, J., and Crosson, S.  2009. Model-based deconvolution of cell cycle time-series data reveals gene expression details at high resolution. PLoS Comput Biol 5: e1000460; doi:10.1371/journal.pcbi.1000460.

Idnurm, A., and Crosson, S.  2009.  The photobiology of microbial pathogenesis.  PLoS Pathog 5: e1000470. doi:10.1371/journal.ppat.1000470.

Boutte, C.C., Srinivasan, B.S., Flannick, J.A., Novak, A.F., Martens, A.T., Batzoglou, S., Viollier, P.H., and Crosson, S.  2008.  Genetic and computational identification of a conserved bacterial metabolic module.  PLoS Genet 4: e1000310; doi:10.1371/journal.pgen.1000310.

Siegal-Gaskins, D., and Crosson, S.  2008.  Tightly-regulated and heritable division control in single bacterial cells.  Biophys J. 95: 2063-2072.

Purcell, E.B. and Crosson, S.  2008.  Photoregulation in prokaryotes.  Curr. Opin. Microbiol. 11:168-178.

Purcell, E.B., Boutte, C.C., and Crosson, S.  2008.  Two-Component Signaling Systems and Cell Cycle Control in Caulobacter crescentus.  In Bacterial Signal Transduction: Networks and Drug Targets.  ed. R. Utsumi.  Landes-Eurekah.  Austin, TX.

Kennis, J.T.M, and Crosson, S.  2007.  A bacterial pathogen sees the light.  Science 317:1041-1042.

Purcell, E.B., Siegal-Gaskins, D., Rawling, D.C., Fiebig, A., and Crosson, S. 2007.  A photosensory two-component system regulates bacterial cell attachment.  Proc. Natl. Acad. Sci. USA. 104:18241-18246.