3T50

X-ray structure of the LOV domain from the LOV-HK sensory protein from Brucella abortus (dark state).

Summary for 3T50

• Entry DOI: 10.2210/pdb3t50/pdb
• Descriptor: Blue-light-activated histidine kinase, FLAVIN MONONUCLEOTIDE (3 entities in total)
• Functional Keywords: pas superfamily, blue-light photoreceptor, fmn binding, transferase
• Biological source: Brucella melitensis
• Total number of polymer chains: 2
• Total formula weight: 29753.56

Authors

Rinaldi, J.J.,Klinke, S.,Goldbaum, F.A. (deposition date: 2011-07-26, release date: 2012-06-13, Last modification date: 2023-09-13)

Primary citation

Rinaldi, J.,Gallo, M.,Klinke, S.,Paris, G.,Bonomi, H.R.,Bogomolni, R.A.,Cicero, D.O.,Goldbaum, F.A.
The Beta-Scaffold of the LOV Domain of the Brucella Light-Activated Histidine Kinase Is a Key Element for Signal Transduction
J.Mol.Biol., 420:112-127, 2012

PubMed Abstract: 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 α/β PAS (PER-ARNT-SIM) domain fold and binds the FMN cofactor within a conserved pocket. The domain dimerizes through the hydrophobic β-scaffold in an antiparallel way. Our results point to the β-scaffold as a key element in the light activation, validating a conserved structural basis for light-to-signal propagation in LOV proteins.

PubMed: 22504229
DOI: 10.1016/j.jmb.2012.04.006

Experimental method

X-RAY DIFFRACTION (1.64 Å)