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Blue-Light-Activated Histidine Kinases: Two-Component Sensors in Bacteria

Swartz, Trevor E., Tseng, Tong-Seung, Frederickson, Marcus A., Paris, Gastón, Comerci, Diego J., Rajashekara, Gireesh, Kim, Jung-Gun, Mudgett, Mary Beth, Splitter, Gary A., Ugalde, Rodolfo A., Goldbaum, Fernando A., Briggs, Winslow R., Bogomolni, Roberto A.
Science 2007 v.317 no.5841 pp. 1090-1093
Brucella melitensis biovar Abortus, Erythrobacter litoralis, Pseudomonas syringae, algae, bacteria, blue light, chemotaxis, gene expression, histidine kinase, macrophages, mutants, photochemistry, photoreceptors, phototaxis, prokaryotic cells, receptors, virulence
Histidine kinases, used for environmental sensing by bacterial two-component systems, are involved in regulation of bacterial gene expression, chemotaxis, phototaxis, and virulence. Flavin-containing domains function as light-sensory modules in plant and algal phototropins and in fungal blue-light receptors. We have discovered that the prokaryotes Brucella melitensis, Brucella abortus, Erythrobacter litoralis, and Pseudomonas syringae contain light-activated histidine kinases that bind a flavin chromophore and undergo photochemistry indicative of cysteinyl-flavin adduct formation. Infection of macrophages by B. abortus was stimulated by light in the wild type but was limited in photochemically inactive and null mutants, indicating that the flavin-containing histidine kinase functions as a photoreceptor regulating B. abortus virulence.