INVESTIGADORES
ZORREGUIETA Angeles
congresos y reuniones científicas
Título:
The LOV histidine kinase of R. leguminosarum regulates the secretion of EPS and flagellar proteins
Autor/es:
BONOMI, H.; POSADAS, D. M.; PARIS, G.; CARRICA, MC; ZORREGUIETA, A; BOGOMOLNI, R; GOLDBAUM, F. A.
Lugar:
Tucumán
Reunión:
Congreso; SAIB; 2009
Institución organizadora:
SAIB
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-HKmutant 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
two-hybrid 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