IIBBA   05544
INSTITUTO DE INVESTIGACIONES BIOQUIMICAS DE BUENOS AIRES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
THE LOV HISTIDINE KINASE OF R. leguminosarum REGULATES THE SECRETION OF EPS AND FLAGELLAR PROTEINS
Autor/es:
HERNÁN R. BONOMI; DIANA POSADAS; GASTON PARIS; MARIELA DEL CARMEN CARRICA; ROBERTO A. BOGOMOLNI; ANGELES ZORREGUIETA; FERNANDO A. GOLDBAUM
Lugar:
Tucumán, Argentina
Reunión:
Congreso; XLV Reunión Anual Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2009
Institución organizadora:
Sociedad Argentina de Investigación Bioquímica
Resumen:
Rhizobium leguminosarum is able to fix nitrogen and form
symbiotic interactions with pea plants. Fixed nitrogen is made
available to the plant which in turn provides carbon nutrients to the
bacteria. Light, oxygen and voltage (LOV) domain are blue light
photoreceptor modules that bind FMN as cofactor and undergo a
photocycle upon illumination. In a previous work we have
identified and characterized a LOV histidine kinase (LOV-HK)
from the related bacteria Brucella. Searches in genomic databases
of R. leguminosarum bv. viciae 3841 allowed us to identify a gene
that encodes for a 345 amino acid protein that has a N-terminal LOV
domain and C-terminal histidine kinase domain and lacks the
central PAS domain present in Brucella LOV-HK. The production
of exopolysaccharide (EPS) in R. leguminosarum is down regulated
by light and this effect is not observed a LOV-HK mutant strain. The
flagellin proteins are down regulated in R. leguminosarum grown in
light as compared with the bacteria grown in the dark. The pattern of
flagellar proteins from the R. leguminosarum LOV-HK mutant was
not different between light and dark and it is similar to the one of R.
leguminosarum wt cells grown in the dark. Using bacterial twohybrid
assay we indentified two single domain response regulators
as partners of LOV-HK protein. These results confirm that LOV-HK
is working as blue light photoreceptor in Rhizobium.