IIBBA   05544
INSTITUTO DE INVESTIGACIONES BIOQUIMICAS DE BUENOS AIRES
Unidad Ejecutora - UE
artículos
Título:
The β-Scaffold of the LOV Domain of the Brucella Light-Activated Histidine Kinase Is a Key Element for Signal Transduction.
Autor/es:
JIMENA RINALDI*; MARIANA GALLO* ; SEBASTIAN KINKLE; GASTÓN PARIS; HERNÁN BONOMI ; ROBERTO A. BOGOLMINI; DANIEL O. CICERO; FERNANDO GOLDBAUM
Revista:
JOURNAL OF MOLECULAR BIOLOGY
Editorial:
ACADEMIC PRESS LTD-ELSEVIER SCIENCE LTD
Referencias:
Lugar: Amsterdam; Año: 2012 vol. 420 p. 112 - 127
ISSN:
0022-2836
Resumen:
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.