GNAPrincipal Researcher:

Gastón Paris, Ph.D.
T: +54 11 4899-5500 int 5612


We study the biological role of bacterial protein photoreceptors such as the light sensing proteins belonging to the LOV, BLUF and bacteriophytochrome families. We use a combined approach of molecular biology, biochemistry and biophysics in order to characterize the mechanisms used by these photoreceptors to sense the light and the induced molecular changes when the protein is activated. These techniques include cloning of the genes which code for the protein photoreceptors, recombinant protein expression and purification, site directed mutagenesis and structural characterization using circular dicroism, laser light scattering, X-ray crystallography and NMR. We also use different spectroscopic techniques and biochemical assays to study the photoreceptor proteins.
To study the in vivo role of photoreceptor, we generate knock-out mutants in the photoreceptors genes and determine the effects on the different cellular functions. We also characterize the components of the signal transduction pathway that are initiated by the photoreceptors.


SELECTED PUBLICATIONS   –   -> Full list of publications

Bitrian, M., González, R. H., Paris, G., Hellingwerf, K. J., Nudel, C. B.
«Blue-light-dependent inhibition of twitching motility in Acinetobacter baylyi ADP1: additive involvement of three BLUF-domain-containing proteins»
Microbiology 159 (2014) 1828-1841.

Carrica, M., Fernández, I., Sieira, R., Paris, G., Goldbaum F.A.
«The two-component systems PrrBA and NtrYX co-ordinately regulate the adaptation of Brucella abortus to an oxygen-limited environment»
Molecular Microbiology 88(2) (2013) 222-233.

Bonomi, H.R.*, Posadas, D.*, Paris, G.*, Carrica, M., Frederickson, M., Pietrasanta, L.I., Bogomolni, R.A., Zorreguieta, A., Goldbaum, F.A.
«Light regulates attachment, exopolysaccharide production, and nodulation in Rhizobium leguminosarum trought a LOV-histidine kinase photoreceptor»
Proceedings National Academy of Science USA 109 (2012) 12123-12128.
* Los autores contribuyeron igualmente en este trabajo.

Rinaldi, J., Gallo, M., Klinke, S., Paris, G., Bonomi, H.R., Bogomolni, R.A., Cicero, D.O., Goldbaum, F.A.
«The β-scaffold of the LOV domain of the Brucella light activated histidine kinase is a key element for signal transduction. «
Journal of Molecular Biology 420 (2012) 112-127.

Swartz et al.
“Blue-light-activated histidine kinases: two-component sensors in bacteria”
Science 317 (2007) 1090-1093.