Literature summary for 1.14.14.B14 extracted from

Drees, S.L.; Ernst, S.; Belviso, B.D.; Jagmann, N.; Hennecke, U.; Fetzner, S.
PqsL uses reduced flavin to produce 2-hydroxylaminobenzoylacetate, a preferred PqsBC substrate in alkyl quinolone biosynthesis in Pseudomonas aeruginosa (2018), J. Biol. Chem., 293, 9345-9357 .

Search for more literature for 1.14.14.B14

Crystallization (Commentary)

Crystallization (Comment)	Organism
analysis of the PqsL structure (PDB ID 2X3N), which has been solved to a resolution of 1.75 A and remodeling of a loop region, which aligns with a loop reported to be involved in NADPH and FAD binding in pHBH, comparison to the structure of pHBH of Pseudomonas fluorescens (PDB code 1PBE), structure-function analysis, detailed overview. The conformation found in PqsL is closer to the open state, which is rather unusual for a group A monooxygenase without substrate bound. The enzyme is not capable of binding NAD(P)H in the alleged mode because several of the crucial positions are replaced by dysfunctional substitutions	Pseudomonas aeruginosa

Crystallization (Comment)

Organism

analysis of the PqsL structure (PDB ID 2X3N), which has been solved to a resolution of 1.75 A and remodeling of a loop region, which aligns with a loop reported to be involved in NADPH and FAD binding in pHBH, comparison to the structure of pHBH of Pseudomonas fluorescens (PDB code 1PBE), structure-function analysis, detailed overview. The conformation found in PqsL is closer to the open state, which is rather unusual for a group A monooxygenase without substrate bound. The enzyme is not capable of binding NAD(P)H in the alleged mode because several of the crucial positions are replaced by dysfunctional substitutions

Pseudomonas aeruginosa

Protein Variants

Protein Variants	Comment	Organism
additional information	in vitro reconstitution of the PqsL/PqsBC reaction is feasible by using the FAD reductase HpaC, the AQ:AQNO ratio is increased in an hpaC-deletion mutant of Pseudomonas aeruginosa strain PAO1 compared with the ratio in the wild-type strain	Pseudomonas aeruginosa

Inhibitors

Inhibitors	Comment	Organism	Structure
additional information	product inhibition of PqsL is possible	Pseudomonas aeruginosa

Natural Substrates/ Products (Substrates)

Natural Substrates	Organism	Comment (Nat. Sub.)	Natural Products	Comment (Nat. Pro.)	Rev.
2-aminobenzoylacetate + FADH2 + O2	Pseudomonas aeruginosa	-	2-hydroxylaminobenzoylacetate + FAD + H2O	-	?
2-aminobenzoylacetate + FADH2 + O2	Pseudomonas aeruginosa ATCC 15692	-	2-hydroxylaminobenzoylacetate + FAD + H2O	-	?
2-aminobenzoylacetate + FADH2 + O2	Pseudomonas aeruginosa 1C	-	2-hydroxylaminobenzoylacetate + FAD + H2O	-	?
2-aminobenzoylacetate + FADH2 + O2	Pseudomonas aeruginosa PRS 101	-	2-hydroxylaminobenzoylacetate + FAD + H2O	-	?
2-aminobenzoylacetate + FADH2 + O2	Pseudomonas aeruginosa DSM 22644	-	2-hydroxylaminobenzoylacetate + FAD + H2O	-	?
2-aminobenzoylacetate + FADH2 + O2	Pseudomonas aeruginosa CIP 104116	-	2-hydroxylaminobenzoylacetate + FAD + H2O	-	?
2-aminobenzoylacetate + FADH2 + O2	Pseudomonas aeruginosa LMG 12228	-	2-hydroxylaminobenzoylacetate + FAD + H2O	-	?
2-aminobenzoylacetate + FADH2 + O2	Pseudomonas aeruginosa JCM 14847	-	2-hydroxylaminobenzoylacetate + FAD + H2O	-	?
additional information	Pseudomonas aeruginosa	PqsL uses reduced flavin to produce 2-hydroxylaminobenzoylacetate, a preferred PqsBC substrate in alkyl quinolone biosynthesis in Pseudomonas aeruginosa	?	-	-
additional information	Pseudomonas aeruginosa ATCC 15692	PqsL uses reduced flavin to produce 2-hydroxylaminobenzoylacetate, a preferred PqsBC substrate in alkyl quinolone biosynthesis in Pseudomonas aeruginosa	?	-	-
additional information	Pseudomonas aeruginosa 1C	PqsL uses reduced flavin to produce 2-hydroxylaminobenzoylacetate, a preferred PqsBC substrate in alkyl quinolone biosynthesis in Pseudomonas aeruginosa	?	-	-
additional information	Pseudomonas aeruginosa PRS 101	PqsL uses reduced flavin to produce 2-hydroxylaminobenzoylacetate, a preferred PqsBC substrate in alkyl quinolone biosynthesis in Pseudomonas aeruginosa	?	-	-
additional information	Pseudomonas aeruginosa DSM 22644	PqsL uses reduced flavin to produce 2-hydroxylaminobenzoylacetate, a preferred PqsBC substrate in alkyl quinolone biosynthesis in Pseudomonas aeruginosa	?	-	-
additional information	Pseudomonas aeruginosa CIP 104116	PqsL uses reduced flavin to produce 2-hydroxylaminobenzoylacetate, a preferred PqsBC substrate in alkyl quinolone biosynthesis in Pseudomonas aeruginosa	?	-	-
additional information	Pseudomonas aeruginosa LMG 12228	PqsL uses reduced flavin to produce 2-hydroxylaminobenzoylacetate, a preferred PqsBC substrate in alkyl quinolone biosynthesis in Pseudomonas aeruginosa	?	-	-
additional information	Pseudomonas aeruginosa JCM 14847	PqsL uses reduced flavin to produce 2-hydroxylaminobenzoylacetate, a preferred PqsBC substrate in alkyl quinolone biosynthesis in Pseudomonas aeruginosa	?	-	-

Organism

Organism	UniProt	Comment	Textmining
Pseudomonas aeruginosa	Q9HWJ1	-	-
Pseudomonas aeruginosa 1C	Q9HWJ1	-	-
Pseudomonas aeruginosa ATCC 15692	Q9HWJ1	-	-
Pseudomonas aeruginosa CIP 104116	Q9HWJ1	-	-
Pseudomonas aeruginosa DSM 22644	Q9HWJ1	-	-
Pseudomonas aeruginosa JCM 14847	Q9HWJ1	-	-
Pseudomonas aeruginosa LMG 12228	Q9HWJ1	-	-
Pseudomonas aeruginosa PRS 101	Q9HWJ1	-	-

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.
2-aminobenzoylacetate + FADH2 + O2	-	Pseudomonas aeruginosa	2-hydroxylaminobenzoylacetate + FAD + H2O	-	?
2-aminobenzoylacetate + FADH2 + O2	-	Pseudomonas aeruginosa ATCC 15692	2-hydroxylaminobenzoylacetate + FAD + H2O	-	?
2-aminobenzoylacetate + FADH2 + O2	-	Pseudomonas aeruginosa 1C	2-hydroxylaminobenzoylacetate + FAD + H2O	-	?
2-aminobenzoylacetate + FADH2 + O2	-	Pseudomonas aeruginosa PRS 101	2-hydroxylaminobenzoylacetate + FAD + H2O	-	?
2-aminobenzoylacetate + FADH2 + O2	-	Pseudomonas aeruginosa DSM 22644	2-hydroxylaminobenzoylacetate + FAD + H2O	-	?
2-aminobenzoylacetate + FADH2 + O2	-	Pseudomonas aeruginosa CIP 104116	2-hydroxylaminobenzoylacetate + FAD + H2O	-	?
2-aminobenzoylacetate + FADH2 + O2	-	Pseudomonas aeruginosa LMG 12228	2-hydroxylaminobenzoylacetate + FAD + H2O	-	?
2-aminobenzoylacetate + FADH2 + O2	-	Pseudomonas aeruginosa JCM 14847	2-hydroxylaminobenzoylacetate + FAD + H2O	-	?
additional information	PqsL uses reduced flavin to produce 2-hydroxylaminobenzoylacetate, a preferred PqsBC substrate in alkyl quinolone biosynthesis in Pseudomonas aeruginosa	Pseudomonas aeruginosa	?	-	-
additional information	PqsL uses reduced flavin to produce 2-hydroxylaminobenzoylacetate, a preferred PqsBC substrate in alkyl quinolone biosynthesis in Pseudomonas aeruginosa, product identification by LC-MS. FAD reductase HpaC (UniProt Q9HWT6) supports PqsL activity in the coupled PqsL/PqsBC assay	Pseudomonas aeruginosa	?	-	-
additional information	PqsL uses reduced flavin to produce 2-hydroxylaminobenzoylacetate, a preferred PqsBC substrate in alkyl quinolone biosynthesis in Pseudomonas aeruginosa	Pseudomonas aeruginosa ATCC 15692	?	-	-
additional information	PqsL uses reduced flavin to produce 2-hydroxylaminobenzoylacetate, a preferred PqsBC substrate in alkyl quinolone biosynthesis in Pseudomonas aeruginosa, product identification by LC-MS. FAD reductase HpaC (UniProt Q9HWT6) supports PqsL activity in the coupled PqsL/PqsBC assay	Pseudomonas aeruginosa ATCC 15692	?	-	-
additional information	PqsL uses reduced flavin to produce 2-hydroxylaminobenzoylacetate, a preferred PqsBC substrate in alkyl quinolone biosynthesis in Pseudomonas aeruginosa	Pseudomonas aeruginosa 1C	?	-	-
additional information	PqsL uses reduced flavin to produce 2-hydroxylaminobenzoylacetate, a preferred PqsBC substrate in alkyl quinolone biosynthesis in Pseudomonas aeruginosa, product identification by LC-MS. FAD reductase HpaC (UniProt Q9HWT6) supports PqsL activity in the coupled PqsL/PqsBC assay	Pseudomonas aeruginosa 1C	?	-	-
additional information	PqsL uses reduced flavin to produce 2-hydroxylaminobenzoylacetate, a preferred PqsBC substrate in alkyl quinolone biosynthesis in Pseudomonas aeruginosa	Pseudomonas aeruginosa PRS 101	?	-	-
additional information	PqsL uses reduced flavin to produce 2-hydroxylaminobenzoylacetate, a preferred PqsBC substrate in alkyl quinolone biosynthesis in Pseudomonas aeruginosa, product identification by LC-MS. FAD reductase HpaC (UniProt Q9HWT6) supports PqsL activity in the coupled PqsL/PqsBC assay	Pseudomonas aeruginosa PRS 101	?	-	-
additional information	PqsL uses reduced flavin to produce 2-hydroxylaminobenzoylacetate, a preferred PqsBC substrate in alkyl quinolone biosynthesis in Pseudomonas aeruginosa	Pseudomonas aeruginosa DSM 22644	?	-	-
additional information	PqsL uses reduced flavin to produce 2-hydroxylaminobenzoylacetate, a preferred PqsBC substrate in alkyl quinolone biosynthesis in Pseudomonas aeruginosa, product identification by LC-MS. FAD reductase HpaC (UniProt Q9HWT6) supports PqsL activity in the coupled PqsL/PqsBC assay	Pseudomonas aeruginosa DSM 22644	?	-	-
additional information	PqsL uses reduced flavin to produce 2-hydroxylaminobenzoylacetate, a preferred PqsBC substrate in alkyl quinolone biosynthesis in Pseudomonas aeruginosa	Pseudomonas aeruginosa CIP 104116	?	-	-
additional information	PqsL uses reduced flavin to produce 2-hydroxylaminobenzoylacetate, a preferred PqsBC substrate in alkyl quinolone biosynthesis in Pseudomonas aeruginosa, product identification by LC-MS. FAD reductase HpaC (UniProt Q9HWT6) supports PqsL activity in the coupled PqsL/PqsBC assay	Pseudomonas aeruginosa CIP 104116	?	-	-
additional information	PqsL uses reduced flavin to produce 2-hydroxylaminobenzoylacetate, a preferred PqsBC substrate in alkyl quinolone biosynthesis in Pseudomonas aeruginosa	Pseudomonas aeruginosa LMG 12228	?	-	-
additional information	PqsL uses reduced flavin to produce 2-hydroxylaminobenzoylacetate, a preferred PqsBC substrate in alkyl quinolone biosynthesis in Pseudomonas aeruginosa, product identification by LC-MS. FAD reductase HpaC (UniProt Q9HWT6) supports PqsL activity in the coupled PqsL/PqsBC assay	Pseudomonas aeruginosa LMG 12228	?	-	-
additional information	PqsL uses reduced flavin to produce 2-hydroxylaminobenzoylacetate, a preferred PqsBC substrate in alkyl quinolone biosynthesis in Pseudomonas aeruginosa	Pseudomonas aeruginosa JCM 14847	?	-	-
additional information	PqsL uses reduced flavin to produce 2-hydroxylaminobenzoylacetate, a preferred PqsBC substrate in alkyl quinolone biosynthesis in Pseudomonas aeruginosa, product identification by LC-MS. FAD reductase HpaC (UniProt Q9HWT6) supports PqsL activity in the coupled PqsL/PqsBC assay	Pseudomonas aeruginosa JCM 14847	?	-	-

Synonyms

Synonyms	Comment	Organism
PA4190	-	Pseudomonas aeruginosa
PqsL	-	Pseudomonas aeruginosa

Temperature Optimum [°C]

Temperature Optimum [°C]	Temperature Optimum Maximum [°C]	Comment	Organism
30	37	assay at	Pseudomonas aeruginosa

pH Optimum

pH Optimum Minimum	pH Optimum Maximum	Comment	Organism
7.3	9.5	assay at	Pseudomonas aeruginosa

Cofactor

Cofactor	Comment	Organism
FAD	the Redox potential of PqsL is sufficiently positive for direct reduction by free flavin, determination of a two-electron midpoint potential of -140 mV for the PqsL-internal FAD	Pseudomonas aeruginosa
FMN	-	Pseudomonas aeruginosa
additional information	PqsL is able to receive electrons from reduced FAD. Alternatively, PqsL might exchange its internal FAD cofactor for FADH2, but because the reaction can be supported by reduced FMN as well (albeit with lower efficiency), a cofactor exchange is rather unlikely. PqsL depends on free reduced flavin as electron donor instead of NAD(P)H. The enzyme is not capable of binding NAD(P)H in the alleged mode because several of the crucial positions are replaced by dysfunctional substitutions	Pseudomonas aeruginosa

General Information

General Information	Comment	Organism
evolution	enzyme PqsL belongs to the class A flavoprotein monooxygenases	Pseudomonas aeruginosa
metabolism	2-alkyl-4-hydroxyquinoline-N-oxide (AQNO) biosynthesis involves the enzymes encoded by the pqsABCDE operon, which mediate 2-alkyl-4-hydroxyquinoline biosynthesis from anthranilic acid and activated fatty acids, and additionally requires PqsL, a putative flavin-dependent monooxygenase encoded by a presumably monocistronic gene. AQNO biosynthesis branches off from 2-ABA or an immediate downstream intermediate. Biosynthesis of alkyl quinolones in Pseudomonas aeruginosa and possible reactions for 2-heptyl-4-hydroxyquinoline-N-oxide (HQNO) synthesis. FAD reductase HpaC supports PqsL activity in the coupled PqsL/PqsBC assay. Deletion of hpaC in Pseudomonas aeruginosa strain PAO1 influences the HQNO to HHQ ratio	Pseudomonas aeruginosa
additional information	PqsL structurally resembles class A flavoprotein monooxygenases such as p-hydroxybenzoate 3-hydroxylase (pHBH, EC 1.14.13.2) and 3-hydroxybenzoate 6-hydroxylase (EC 1.14.13.24). But unlike related enzymes, PqsL hydroxylates a primary aromatic amine group, and it does not use NAD(P)H as cosubstrate, but unexpectedly requires reduced flavin as electron donor. A structural comparison with pHBH, the model enzyme of class A flavoprotein monooxygenases, reveals that structural features associated with NAD(P)H binding are missing in PqsL	Pseudomonas aeruginosa
physiological function	alkyl hydroxyquinoline N-oxides (AQNOs) are antibiotic compounds produced by the opportunistic bacterial pathogen Pseudomonas aeruginosa. They are products of the alkyl quinolone (AQ) biosynthetic pathway, which also generates the quorum-sensing molecules 2-heptyl-4(1H)-quinolone (HHQ) and 2-heptyl-3-hydroxy-4(1H)-quinolone (PQS). PqsL is the key enzyme for AQNO production. PqsL is active toward 2-aminobenzoylacetate (2-ABA), the central intermediate of the AQ pathway, and forms the unstable compound 2-hydroxylaminobenzoylacetate, which is preferred over 2-ABA as a substrate of the downstream enzyme PqsBC. Although 2-heptyl-3-hydroxy-4(1H)-quinolone (Pseudomonas quinolone signal, PQS) and its immediate biosynthetic precursor 2-heptyl-4(1H)-quinolone (HHQ) mainly serve as quorum sensing signals, contributing to the control of virulence gene expression, 2-heptyl-4-hydroxyquinoline-N-oxide (HQNO) acts as a toxin against both microorganisms and eukaryotic cells. PqsL is the key enzyme for biosynthesis of HQNO, it catalyzes the N-oxidation of a biosynthetic precursor molecule other than HHQ	Pseudomonas aeruginosa