Literature summary for 2.7.13.3 extracted from

Sycz, G.; Carrica, M.C.; Tseng, T.S.; Bogomolni, R.A.; Briggs, W.R.; Goldbaum, F.A.; Paris, G.
LOV histidine kinase modulates the general stress response system and affects the virB operon expression in Brucella abortus (2015), PLoS ONE, 10, e0124058.

Activating Compound

Activating Compound	Comment	Organism	Structure
additional information	exposure to light increases the autophosphorylation activity of the enzyme	Brucella abortus

Cloned(Commentary)

Cloned (Comment)	Organism
gene BAB2_0652, recombinant expression f the enzyme in a two-hybrid system with PdhS in frame with the lambdacl gene, coexpression with gene pdhS, recombinant expression of His-tagged lovhk and hk domains in Escherichia coli strain BL21(DE3) pLysS from pET24a plasmid, coexpression of phyR and lovR. Antibiotic resistance complementation assays with the enzyme in Escherichia coli, overview. Realtime quantitative RT-PCR expression analysis	Brucella abortus

Cloned (Comment)

Organism

gene BAB2_0652, recombinant expression f the enzyme in a two-hybrid system with PdhS in frame with the lambdacl gene, coexpression with gene pdhS, recombinant expression of His-tagged lovhk and hk domains in Escherichia coli strain BL21(DE3) pLysS from pET24a plasmid, coexpression of phyR and lovR. Antibiotic resistance complementation assays with the enzyme in Escherichia coli, overview. Realtime quantitative RT-PCR expression analysis

Brucella abortus

Protein Variants

Protein Variants	Comment	Organism
additional information	construction of a LOVHK knockout mutant	Brucella abortus

Metals/Ions

Metals/Ions	Comment	Organism	Structure
Mg2+	required	Brucella abortus

Natural Substrates/ Products (Substrates)

Natural Substrates	Organism	Comment (Nat. Sub.)	Natural Products	Comment (Nat. Pro.)	Rev.
ATP + protein L-histidine	Brucella abortus	-	ADP + protein N-phospho-L-histidine	-	?
ATP + protein L-histidine	Brucella abortus 2308	-	ADP + protein N-phospho-L-histidine	-	?
additional information	Brucella abortus	LOVHK is able to phosphotransfer to the central regulator of the GSR system in Brucella, specific interaction with its cognate response regulators	?	-	?
additional information	Brucella abortus 2308	LOVHK is able to phosphotransfer to the central regulator of the GSR system in Brucella, specific interaction with its cognate response regulators	?	-	?

Organism

Organism	UniProt	Comment	Textmining
Brucella abortus	Q2YKK7	-	-
Brucella abortus 2308	Q2YKK7	-	-

Posttranslational Modification

Posttranslational Modification	Comment	Organism
phosphoprotein	activation of LOVHK by blue-light increases the autophosphorylation activity of the HK domain of the histidine kinase	Brucella abortus

Purification (Commentary)

Purification (Comment)	Organism
recombinant His-tagged LOVHK from Escherichia coli strain BL21(DE3) by nickel affinity chromatography	Brucella abortus

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.
ATP + protein L-histidine	-	Brucella abortus	ADP + protein N-phospho-L-histidine	-	?
ATP + protein L-histidine	-	Brucella abortus 2308	ADP + protein N-phospho-L-histidine	-	?
additional information	LOVHK is able to phosphotransfer to the central regulator of the GSR system in Brucella, specific interaction with its cognate response regulators	Brucella abortus	?	-	?
additional information	LOVHK is able to phosphotransfer to the central regulator of the GSR system in Brucella, specific interaction with its cognate response regulators	Brucella abortus 2308	?	-	?

Synonyms

Synonyms	Comment	Organism
BA-LOV-histidine kinase	UniProt	Brucella abortus
BA-LOV-HK	UniProt	Brucella abortus
BAB2_0652	-	Brucella abortus
blue-light-activated histidine kinase	UniProt	Brucella abortus
LOV	-	Brucella abortus
LOVHK	-	Brucella abortus

Cofactor

Cofactor	Comment	Organism	Structure
ATP	-	Brucella abortus
additional information	LOV domains are blue-light sensory modules which bind a flavin molecule as cofactor. Activation of LOVHK by blue-light increases the autophosphorylation activity of the HK domain	Brucella abortus

General Information

General Information	Comment	Organism
evolution	Brucella spp. genomes encode a LOV-domain-containing protein that is associated to a PAS (Per, Arnt and Sim) domain plus a HK domain (LOVHK), which belongs to the HWE family	Brucella abortus
malfunction	in the absence of LOVHK the expression of the virB operon is downregulated. LOVHK plays a role in the intracellular survival of Brucella, since deletion of this gene in Brucella abortus shows an attenuated phenotype in cell-culture infection assays. PhyR expression is decreased in the lovhk mutant	Brucella abortus
additional information	LOV domains are blue-light sensory modules which bind a flavin molecule as cofactor	Brucella abortus
physiological function	LOV histidine kinase positively regulates the general stress response system and affects the virB operon expression in Brucella abortus. The Brucella genome encodes a sensor histidine kinase containing a LOV domain upstream from the kinase, LOVHK, which plays an important role in light-regulated Brucella virulence. The intracellular signaling pathway is initiated by the light sensor LOVHK, which functionally interacts with two response regulators: PhyR and LovR, constituting a functional two-component signal-transduction system. LOVHK contributes to the activation of the general stress response (GSR) system in Brucella via PhyR, the main regulator of the general stress response system, while LovR is proposed to be a phosphate-sink for LOVHK, decreasing its phosphorylation state. LOVHK plays a role in the intracellular survival of Brucella and in defense of stress induced by starvation. LOVHK signaling cascade, overview	Brucella abortus