Cloned (Comment) | Organism |
---|---|
gene arsh, expression as N-terminallyy His-tagged enzyme in Escherichia coli strain BL21(DE3) | Synechocystis sp. |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
dicoumarol | - |
Synechocystis sp. | |
NADP+ | NADP+ acts as a competitive inhibitor for NADPH binding at the active site of an enzyme | Synechocystis sp. |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
additional information | - |
additional information | stopped-flow and steady-state kinetics, overview | Synechocystis sp. | |
0.0012 | - |
dibromothymoquinone | pH 8.0, 25°C, recombinant His-tagged enzyme | Synechocystis sp. | |
0.0013 | - |
2,5-dimethyl-4-benzoquinone | pH 8.0, 25°C, recombinant His-tagged enzyme | Synechocystis sp. | |
0.0028 | - |
duroquinone | pH 8.0, 25°C, recombinant His-tagged enzyme | Synechocystis sp. | |
0.0057 | - |
menadione | pH 8.0, 25°C, recombinant His-tagged enzyme | Synechocystis sp. | |
0.0119 | - |
coenzyme Q10 | pH 8.0, 25°C, recombinant His-tagged enzyme | Synechocystis sp. | |
0.0237 | - |
2-Hydroxy-1,4-naphthoquinone | pH 8.0, 25°C, recombinant His-tagged enzyme | Synechocystis sp. | |
0.0315 | - |
NADPH | pH 8.0, 25°C, recombinant His-tagged enzyme | Synechocystis sp. | |
0.0345 | - |
anthraquinone-2-sulfonate | pH 8.0, 25°C, recombinant His-tagged enzyme | Synechocystis sp. |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
NADPH + H+ + a quinone | Synechocystis sp. | the catalytic cycle of ArsH consists of the acceptance of two electrons from NADPH to reduce the flavin cofactor (reductive half-reaction) and the transfer of these electrons to an acceptor (oxidative half-reaction) | NADP+ + a quinol | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Synechocystis sp. | - |
gene arsH | - |
Reaction | Comment | Organism | Reaction ID |
---|---|---|---|
NADPH + H+ + a quinone = NADP+ + a quinol | ping pong reaction mechanism | Synechocystis sp. |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
additional information | NADH, deazariboflavin, and methylviologen can also act as electron donors | Synechocystis sp. | ? | - |
? | |
NADPH + H+ + 2,5-dimethyl-4-benzoquinone | - |
Synechocystis sp. | NADP+ + 2,5-dimethyl-4-benzoquinonl | - |
? | |
NADPH + H+ + 2-hydroxy-1,4-naphthoquinone | - |
Synechocystis sp. | NADP+ + 2-hydroxy-1,4-naphthoquinol | - |
? | |
NADPH + H+ + a quinone | the catalytic cycle of ArsH consists of the acceptance of two electrons from NADPH to reduce the flavin cofactor (reductive half-reaction) and the transfer of these electrons to an acceptor (oxidative half-reaction) | Synechocystis sp. | NADP+ + a quinol | - |
? | |
NADPH + H+ + anthraquinone-2-sulfonate | - |
Synechocystis sp. | NADP+ + ? | - |
? | |
NADPH + H+ + coenzyme Q10 | - |
Synechocystis sp. | NADP+ + reduced coenzyme Q10 | - |
? | |
NADPH + H+ + dibromothymoquinone | - |
Synechocystis sp. | NADP+ + dibromothymoquinol | - |
? | |
NADPH + H+ + dichlorophenolindophenol | - |
Synechocystis sp. | NADP+ + reduced dichlorophenolindophenol | - |
? | |
NADPH + H+ + duroquinone | - |
Synechocystis sp. | NADP+ + duroquinol | - |
? | |
NADPH + H+ + menadione | - |
Synechocystis sp. | NADP+ + menadiol | - |
? |
Synonyms | Comment | Organism |
---|---|---|
ArsH | - |
Synechocystis sp. |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
25 | - |
assay at | Synechocystis sp. |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
5 | - |
coenzyme Q10 | pH 8.0, 25°C, recombinant His-tagged enzyme | Synechocystis sp. | |
9.4 | - |
anthraquinone-2-sulfonate | pH 8.0, 25°C, recombinant His-tagged enzyme | Synechocystis sp. | |
11 | - |
2-Hydroxy-1,4-naphthoquinone | pH 8.0, 25°C, recombinant His-tagged enzyme | Synechocystis sp. | |
25 | - |
duroquinone | pH 8.0, 25°C, recombinant His-tagged enzyme | Synechocystis sp. | |
26 | - |
menadione | pH 8.0, 25°C, recombinant His-tagged enzyme | Synechocystis sp. | |
35 | - |
dibromothymoquinone | pH 8.0, 25°C, recombinant His-tagged enzyme | Synechocystis sp. | |
36.7 | - |
2,5-dimethyl-4-benzoquinone | pH 8.0, 25°C, recombinant His-tagged enzyme | Synechocystis sp. |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
8 | - |
assay at | Synechocystis sp. |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
FMN | - |
Synechocystis sp. |
IC50 Value | IC50 Value Maximum | Comment | Organism | Inhibitor | Structure |
---|---|---|---|---|---|
0.008 | 0.01 | with dichlorophenolindophenol, pH 8.0, 25°C, recombinant His-tagged enzyme | Synechocystis sp. | dicoumarol |
General Information | Comment | Organism |
---|---|---|
evolution | the enzyme is a member of the family of NADPH-dependent FMN reductases | Synechocystis sp. |
malfunction | arsH mutants are sensitive to the oxidizing agent menadione | Synechocystis sp. |
additional information | although the enzyme is able to stabilize the anionic semiquinone form of the FMN, reduction of quinones involves the hydroquinone form of the flavin cofactor, and the enzymatic reaction occurs through a ping pong-type mechanism. ArsH is able to catalyze one-electron reactions (oxygen and cytocrome c reduction), involving the FMN semiquinone form, but with lower efficiency | Synechocystis sp. |
physiological function | ArsH plays a role in the response to oxidative stress caused by arsenite | Synechocystis sp. |