Literature summary for 3.6.1.18 extracted from

Deka, R.K.; Brautigam, C.A.; Liu, W.Z.; Tomchick, D.R.; Norgard, M.V.
Molecular insights into the enzymatic diversity of flavin-trafficking protein (Ftp; formerly ApbE) in flavoprotein biogenesis in the bacterial periplasm (2016), MicrobiologyOpen, 5, 21-38 .

Crystallization (Commentary)

Crystallization (Comment)	Organism
purified Ftp_Ec mutant variant Y60N complexed with ADP, hanging drop vapor diffusion method, mixing of 0.004 ml of 20 mg/ml protein in Tris, pH 7.5, and 20 mM NaCl, with 0.04 ml of reservoir solution containing 0.2 M NH4NO3, and 20% w/v PEG 3350, and 0.001 ml of 50 mM MgCl2, and 0.001 ml of 50 mM ADP, 20°C, X-ray diffraction structure determination and analysis at 1.85 A resolution, molecular replacement and modelling	Escherichia coli

Crystallization (Comment)

Organism

purified Ftp_Ec mutant variant Y60N complexed with ADP, hanging drop vapor diffusion method, mixing of 0.004 ml of 20 mg/ml protein in Tris, pH 7.5, and 20 mM NaCl, with 0.04 ml of reservoir solution containing 0.2 M NH4NO3, and 20% w/v PEG 3350, and 0.001 ml of 50 mM MgCl2, and 0.001 ml of 50 mM ADP, 20°C, X-ray diffraction structure determination and analysis at 1.85 A resolution, molecular replacement and modelling

Escherichia coli

Protein Variants

Protein Variants	Comment	Organism
E169K	site-directed mutagenesis of the probabale catalytic site residue, the Ftp_EcE169K protein variant does not show binding of FAD, inactive mutant	Escherichia coli
Y60A	site-directed mutagenesis, the engineered protein variant (Ftp_EcY60A) shows Mg2+-dependent FAD diphosphatase activity, but also retains its Mg2+-dependent FMN transferase (EC 2.7.1.180) activity on the protein substrate, indicating that the protein variant enzyme has dual activity	Escherichia coli
Y60N	site-directed mutagenesis, a single amino acid substitution converts it from an FAD-binding protein to a Mg2+-dependent FAD diphosphatase (Ftp_Tp-like)	Escherichia coli

Inhibitors

Inhibitors	Comment	Organism	Structure
EDTA	-	Escherichia coli
EDTA	-	Treponema pallidum

Localization

Localization	Comment	Organism	GeneOntology No.	Textmining
periplasm	-	Treponema pallidum	-	-
periplasm	-	Escherichia coli	-	-

Metals/Ions

Metals/Ions	Comment	Organism	Structure
Mg2+	dependent on, metal-dependent enzyme	Treponema pallidum
Mg2+	dependent on, metal-dependent enzyme, bimetal center in the crystal structure of Escherichia coli Ftp	Escherichia coli

Natural Substrates/ Products (Substrates)

Natural Substrates	Organism	Comment (Nat. Sub.)	Natural Products	Comment (Nat. Pro.)	Rev.
FAD + H2O	Treponema pallidum	-	AMP + FMN	-	?
FAD + H2O	Escherichia coli	-	AMP + FMN	-	?
FAD + H2O	Treponema pallidum Nichols	-	AMP + FMN	-	?

Organism

Organism	UniProt	Comment	Textmining
Escherichia coli	P0AB85	cf. EC 2.7.1.180	-
Treponema pallidum	O83774	cf. EC 2.7.1.180	-

Source Tissue

Source Tissue	Comment	Organism	Textmining

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.
FAD + H2O	-	Treponema pallidum	AMP + FMN	-	?
FAD + H2O	-	Escherichia coli	AMP + FMN	-	?
FAD + H2O	-	Treponema pallidum Nichols	AMP + FMN	-	?
additional information	the flavin-trafficking protein (Ftp) catalyzes the transfer of the FMN moiety of FAD and its covalent binding to the hydroxyl group of a threonine residue in a target flavoprotein (EC 2.7.1.180). The enzyme is capable of flavinylating periplasmic redox-carrying proteins (e.g., RnfG_Ec) via the metal-dependent covalent attachment of FMN. A single amino acid substitution Y60N converts it from an FAD-binding protein to a Mg2+-dependent FAD diphosphatase (Ftp_Tp-like) (EC 3.6.1.18). The engineered protein variant (Ftp_EcY60A) shows Mg2+-dependent FAD diphosphatase activity, but also retains its Mg2+-dependent FMN transferase (EC 2.7.1.180) activity on the protein substrate, indicating that the protein variant enzyme has dual activity. The Ftp_EcY60A protein variant binds FAD, yet rapidly hydrolyzes it and the product FMN dissociates	Escherichia coli	?	-	-
additional information	the flavin-trafficking protein (Ftp) catalyzes the transfer of the FMN moiety of FAD and its covalent binding to the hydroxyl group of a threonine residue in a target flavoprotein (EC 2.7.1.180). The enzyme is capable of flavinylating periplasmic redox-carrying proteins (e.g., RnfG_Ec) via the metal-dependent covalent attachment of FMN. It also displays FAD diphosphatase activity in vitro, hydrolyzing FAD into FMN and AMP (EC 3.6.1.18)	Treponema pallidum	?	-	-
additional information	the flavin-trafficking protein (Ftp) catalyzes the transfer of the FMN moiety of FAD and its covalent binding to the hydroxyl group of a threonine residue in a target flavoprotein (EC 2.7.1.180). The enzyme is capable of flavinylating periplasmic redox-carrying proteins (e.g., RnfG_Ec) via the metal-dependent covalent attachment of FMN. It also displays FAD diphosphatase activity in vitro, hydrolyzing FAD into FMN and AMP (EC 3.6.1.18)	Treponema pallidum Nichols	?	-	-

Synonyms

Synonyms	Comment	Organism
FAD pyrophosphatase	-	Treponema pallidum
FAD pyrophosphatase	-	Escherichia coli
Ftp_Ec	-	Escherichia coli
Ftp_Tp-like	-	Treponema pallidum
Ftp_Tp-like	-	Escherichia coli
metal-dependent FAD pyrophosphatase	-	Treponema pallidum
metal-dependent FAD pyrophosphatase	-	Escherichia coli
Mg2+-dependent FAD pyrophosphatase	-	Treponema pallidum
Mg2+-dependent FAD pyrophosphatase	-	Escherichia coli
More	cf. EC 2.7.1.180	Treponema pallidum
More	cf. EC 2.7.1.180	Escherichia coli

Temperature Optimum [°C]

Temperature Optimum [°C]	Temperature Optimum Maximum [°C]	Comment	Organism
37	-	assay at	Treponema pallidum
37	-	assay at	Escherichia coli

pH Optimum

pH Optimum Minimum	pH Optimum Maximum	Comment	Organism
7.5	-	assay at	Treponema pallidum
7.5	-	assay at	Escherichia coli

General Information

General Information	Comment	Organism
evolution	there likely are two classes of Ftps, one associated with FAD-binding and the other with FAD hydrolysis	Treponema pallidum
evolution	there likely are two classes of Ftps, one associated with FAD-binding and the other with FAD hydrolysis	Escherichia coli
malfunction	a single amino acid substitution Y60N converts it from an FAD-binding protein to a Mg2+-dependent FAD diphosphatase (Ftp_Tp-like). The engineered protein variant (Ftp_EcY60A) shows Mg2+-dependent FAD diphosphatase activity, but also retains its Mg2+-dependent FMN transferase (EC 2.7.1.180) activity on the protein substrate, indicating that the protein variant enzyme has dual activity	Escherichia coli
additional information	the critical residue that contacts the isoalloxazine ring of FAD, is a tyrosine residue in the FAD-binding Ftps	Treponema pallidum
additional information	the critical residue that contacts the isoalloxazine ring of FAD, is a tyrosine residue in the FAD-binding Ftps	Escherichia coli
physiological function	the flavin-trafficking protein (Ftp) catalyzes the transfer of the FMN moiety of FAD to a threonine residue in a target flavoprotein	Escherichia coli
physiological function	the flavin-trafficking protein (Ftp) in the syphillis spirochete Treponema pallidum (Ftp_Tp) is a bacterial metal-dependent FAD diphosphatase that hydrolyzes FAD into AMP and FMN in the periplasm	Treponema pallidum