Structural highlights
Function
[LOVHK_BRUME] Photosensitive kinase that is involved in increased bacterial virulence upon exposure to light. Once ejected from an infected animal host, sunlight acts as an environmental signal that increases the virulence of the bacterium, preparing it for infection of the next host. This photoreceptor protein is directly related to the bacterium's survival and replication within host macrophages.
Publication Abstract from PubMed
Light-oxygen-voltage (LOV) domains are blue-light-activated signaling modules present in a wide range of sensory proteins. Among them, the histidine kinases are the largest group in prokaryotes (LOV-HK). Light modulates the virulence of the pathogenic bacteria Brucella abortus through LOV-HK. One of the striking characteristic of Brucella LOV-HK is the fact that the protein remains activated upon light sensing, without recovering the basal state in the darkness. In contrast, the light state of the isolated LOV domain slowly returns to the dark state. To gain insight into the light activation mechanism, we have characterized by X-ray crystallography and solution NMR spectroscopy the structure of the LOV domain of LOV-HK in the dark state and explored its light-induced conformational changes. The LOV domain adopts the alpha/beta PAS (PER-ARNT-SIM) domain fold and binds the FMN cofactor within a conserved pocket. The domain dimerizes through the hydrophobic beta-scaffold in an antiparallel way. Our results point to the beta-scaffold as a key element in the light activation, validating a conserved structural basis for light-to-signal propagation in LOV proteins.
The beta-Scaffold of the LOV Domain of the Brucella Light-Activated Histidine Kinase Is a Key Element for Signal Transduction.,Rinaldi J, Gallo M, Klinke S, Paris G, Bonomi HR, Bogomolni RA, Cicero DO, Goldbaum FA J Mol Biol. 2012 Jun 29;420(1-2):112-27. Epub 2012 Apr 11. PMID:22504229[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Rinaldi J, Gallo M, Klinke S, Paris G, Bonomi HR, Bogomolni RA, Cicero DO, Goldbaum FA. The beta-Scaffold of the LOV Domain of the Brucella Light-Activated Histidine Kinase Is a Key Element for Signal Transduction. J Mol Biol. 2012 Jun 29;420(1-2):112-27. Epub 2012 Apr 11. PMID:22504229 doi:10.1016/j.jmb.2012.04.006
