Blue-light-activated Histidine kinases function as two-component sensors in bacteria

SWARTZ, T. E., TSENG, T.-S., FREDERICKSON, M. A., PARIS, G., COMERCI, D. J., RAJASHEKARA, G., KIM, J.-G., MUDGETT, M. B., SPLITTER, G. A., UGALDE, R. A., GOLDBAUM, F. A., BRIGGS, W. R. AND BOGOMOLNI, R. A.

SCIENCE

AMER ASSOC ADVANCEMENT SCIENCE

Año: 2007 vol. 317 p. 1090 - 1093

0036-8075

Histidine kinases, used for environmental sensing by bacterial two-component systems, areinvolved in regulation of bacterial gene expression, chemotaxis, phototaxis, and virulence. Flavincontainingdomains function as light-sensory modules in plant and algal phototropins and infungal blue-light receptors. We have discovered that the prokaryotes Brucella melitensis, Brucellaabortus, Erythrobacter litoralis, and Pseudomonas syringae contain light-activated histidinekinases that bind a flavin chromophore and undergo photochemistry indicative of cysteinyl-flavinadduct formation. Infection of macrophages by B. abortus was stimulated by light in the wild typebut was limited in photochemically inactive and null mutants, indicating that the flavin-containinghistidine kinase functions as a photoreceptor regulating B. abortus virulence.