Literature summary for 1.5.1.30 extracted from

Morozov, G.; Porat, N.; Kushnir, T.; Najmuldeen, H.; Adawi, A.; Chalifa-Caspi, V.; Benisty, R.; Ohayon, A.; Liron, O.; Azriel, S.; Malka, I.; Dotan, S.; Portnoi, M.; Piotrowski, A.; Kafka, D.; Hajaj, B.; Fishilevich, T.; Shagan, M.; Tal, M.; Ellis, R.
Flavin reductase contributes to pneumococcal virulence by protecting from oxidative stress and mediating adhesion and elicits protection against pneumococcal challenge (2018), Sci. Rep., 8, 314 .

Activating Compound

Activating Compound	Comment	Organism	Structure
cysteine	recombinant enzyme FlaR (rFlaR) FAD-dependent NADP-reductase is activated in the presence of cysteine, cysteine significantly stimulates rFlaR NADP+-reductase activity	Streptococcus pneumoniae

Application

Application	Comment	Organism
medicine	FlaR's roles in pneumococcal physiology and virulence, combined with its lack of significant homology to human proteins, point towards rFlaR as a vaccine candidate	Streptococcus pneumoniae

Cloned(Commentary)

Cloned (Comment)	Organism
gene flaR, recombinant overexpression of HAT-tagged enzyme FlaR in Escherichia coli	Streptococcus pneumoniae

Protein Variants

Protein Variants	Comment	Organism
additional information	generation of a WU2DELTAflaRkan null mutant strain	Streptococcus pneumoniae

Inhibitors

Inhibitors	Comment	Organism
citrate	-	Streptococcus pneumoniae
EDTA	-	Streptococcus pneumoniae
additional information	recombinant enzyme FlaR (rFlaR) FAD-dependent NADP-reductase activity is inhibited by divalent-chelating agents. Salicylate does not inhibit NADPH production by rFlaR	Streptococcus pneumoniae
nitrilotriacetic acid	NTA	Streptococcus pneumoniae

Localization

Localization	Comment	Organism	GeneOntology No.	Textmining
cell surface	-	Streptococcus pneumoniae	9986	-
cell wall	-	Streptococcus pneumoniae	5618	-
cytoplasm	-	Streptococcus pneumoniae	5737	-

Metals/Ions

Metals/Ions	Comment	Organism	Structure
Fe2+	rFlaR NADP+ reductase activity is Fe2+-dependent, recombinant enzyme FlaR (rFlaR) binds Fe2+ and exhibits FAD-dependent NADP-reductase activity, which increases in the presence of excess Fe2+ and is inhibited by divalent-ion chelating agents	Streptococcus pneumoniae

Molecular Weight [Da]

Molecular Weight [Da]	Molecular Weight Maximum [Da]	Comment	Organism
45000	-	recombinant HAT-tagged enzyme, native PAGE	Streptococcus pneumoniae

Natural Substrates/ Products (Substrates)

Natural Substrates	Organism	Comment (Nat. Sub.)	Natural Products	Comment (Nat. Pro.)	Rev.	Reac.
FAD + NADPH + H+	Streptococcus pneumoniae	-	FADH2 + NADP+	-	r

Organism

Organism	UniProt	Comment	Textmining
Streptococcus pneumoniae	A0A4M3JL10	-	-

Purification (Commentary)

Purification (Comment)	Organism
recombinant HAT-tagged enzyme FlaR from Escherichia coli by nickel affinity chromatography, solubilization with 8 M urea, and dialysis	Streptococcus pneumoniae

Renatured (Commentary)

Renatured (Comment)	Organism
the recombinant FlaR is insoluble under physiological conditions and its purification can be obtained under denaturing conditions in buffer supplemented with 8 M urea. Different refolding conditions are tested for their ability to renature the protein. Dialysis of the denatured protein against buffers at different pH levels reveals that rFlaR can be solubilized at below pH 8.0. The presence of cysteine-rich sequence suggests that the protein has a transitional metal-binding ability. Thus, rFlaR is dialyzed against PBS (pH 7.3) supplemented with 2 mM salts of either transition metal or calcium and magnesium (2 mM of each). rFlaR becomes fully soluble in the presence of 2 mM FeSO4. Partial solubility can be obtained in the presence of 2 mM CoCl2 or CuSO4	Streptococcus pneumoniae

Renatured (Comment)

Organism

the recombinant FlaR is insoluble under physiological conditions and its purification can be obtained under denaturing conditions in buffer supplemented with 8 M urea. Different refolding conditions are tested for their ability to renature the protein. Dialysis of the denatured protein against buffers at different pH levels reveals that rFlaR can be solubilized at below pH 8.0. The presence of cysteine-rich sequence suggests that the protein has a transitional metal-binding ability. Thus, rFlaR is dialyzed against PBS (pH 7.3) supplemented with 2 mM salts of either transition metal or calcium and magnesium (2 mM of each). rFlaR becomes fully soluble in the presence of 2 mM FeSO4. Partial solubility can be obtained in the presence of 2 mM CoCl2 or CuSO4

Streptococcus pneumoniae

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.	Reac.
FAD + NADPH + H+	-	Streptococcus pneumoniae	FADH2 + NADP+	-	r
additional information	significant reduction of NADP+ by rFlaR refolded in the presence Fe2+. Fe2+ is the electron donor in the rFlaR-NADP+ reductase activity	Streptococcus pneumoniae	?	-	-

Subunits

Subunits	Comment	Organism
dimer	2 * 21000, recombinant HAT-tagged enzyme, SDS-PAGE, 2 * 17200, about, sequence calculation	Streptococcus pneumoniae

Synonyms

Synonyms	Comment	Organism
FAD-dependent NADP-reductase	-	Streptococcus pneumoniae
flavin reductase	-	Streptococcus pneumoniae

Cofactor

Cofactor	Comment	Organism	Structure
NADP+	-	Streptococcus pneumoniae
NADPH	-	Streptococcus pneumoniae

General Information

General Information	Comment	Organism
evolution	the flavin reductase DNA sequence of the TIGR4 strain is compared to 29 completely sequenced genomes of Streptococcus pneumoniae. All 29 genomes contain a highly similar locus to SP_RS 02775	Streptococcus pneumoniae
malfunction	a flaR mutant is highly susceptible to H2O2 compared to its wild-type and complemented strains, suggesting a role for FlaR in pneumococcal oxidative stress resistance. The flaR mutant demonstrates significantly decreased mice mortality following intraperitoneal infection. A lack of FlaR does not affect the extent of phagocytosis by primary mouse peritoneal macrophages but reduces adhesion to A549 cells compared to wild-type and complemented strains	Streptococcus pneumoniae
physiological function	flavin reductase contributes to pneumococcal virulence by protecting from oxidative stress and mediating adhesion and elicits protection against pneumococcal challenge, role for FlaR in pneumococcal oxidative stress resistance. FlaR involvement in virulence i.e. adhesion to host cells, mechanism, overview	Streptococcus pneumoniae