Protein Variants | Comment | Organism |
---|---|---|
D188A | site-directed mutagenesis, the mutant shows altered sensitivity to inhibitor aurachin C1-10 compared to the wild-type enzyme, The mutant oxidase is not able to support aerobic growth when expressed in a strain of Escherichia coli without a genomically encoded respiratory oxidase | Escherichia coli |
D188N | site-directed mutagenesis, the mutant shows altered sensitivity to inhibitor aurachin C1-10 compared to the wild-type enzyme | Escherichia coli |
D75E | site-directed mutagenesis at the QH-site of cytochrome bo3, the mutant shows similar activity compared to the wild-type enzyme | Escherichia coli |
D75H | site-directed mutagenesis at the QH-site of cytochrome bo3, the mutant shows highly reduced enzyme activity compared to the wild-type enzyme | Escherichia coli |
D75N | site-directed mutagenesis at the QH-site of cytochrome bo3, the mutant shows highly reduced enzyme activity compared to the wild-type enzyme | Escherichia coli |
D75R | site-directed mutagenesis at the QH-site of cytochrome bo3, the mutant shows highly reduced enzyme activity compared to the wild-type enzyme | Escherichia coli |
H98N | site-directed mutagenesis at the QH-site of cytochrome bo3, the mutant shows highly reduced enzyme activity compared to the wild-type enzyme | Escherichia coli |
H98S | site-directed mutagenesis at the QH-site of cytochrome bo3, the mutant shows highly reduced enzyme activity compared to the wild-type enzyme | Escherichia coli |
H98S | site-directed mutagenesis, the mutant shows altered sensitivity to inhibitor aurachin C1-100 compared to the wild-type enzyme | Escherichia coli |
H98T | site-directed mutagenesis at the QH-site of cytochrome bo3, the mutant shows highly reduced enzyme activity compared to the wild-type enzyme | Escherichia coli |
Q101N | site-directed mutagenesis at the QH-site of cytochrome bo3, the mutant shows highly reduced enzyme activity compared to the wild-type enzyme | Escherichia coli |
R257Q | site-directed mutagenesis, the mutant shows altered sensitivity to inhibitor aurachin C1-10 compared to the wild-type enzyme. The mutant oxidase is not able to support aerobic growth when expressed in a strain of Escherichia coli without a genomically encoded respiratory oxidase | Escherichia coli |
R71D | site-directed mutagenesis at the QH-site of cytochrome bo3, the mutant shows highly reduced enzyme activity compared to the wild-type enzyme | Escherichia coli |
R71D/D75R | site-directed mutagenesis at the QH-site of cytochrome bo3, the mutant shows highly reduced enzyme activity compared to the wild-type enzyme | Escherichia coli |
R71K | site-directed mutagenesis at the QH-site of cytochrome bo3, the mutant shows highly reduced enzyme activity compared to the wild-type enzyme | Escherichia coli |
R71Q | site-directed mutagenesis at the QH-site of cytochrome bo3, the mutant shows highly reduced enzyme activity compared to the wild-type enzyme | Escherichia coli |
WI36A | site-directed mutagenesis, the mutant shows altered sensitivity to inhibitor aurachin C1-10 compared to the wild-type enzyme | Escherichia coli |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
2-heptyl-4-hydroxyquinoline N-oxide | i.e. HQNO, binds stoichiometrically to the enzyme and prevents formation of the ubisemiquinone at the QH-site, but does not displace the ubiquinone-8 bound at the QH-site, enzyme binding kineticss, overview | Escherichia coli | |
aurachin C1-10 | prevents formation of the ubisemiquinone at the QH-site, but appears to compete for quinol binding at the QL-site, enzyme binding kineticss, overview | Escherichia coli | |
additional information | presence of high affinity inhibitors, 2-heptyl-4-hydroxyquinoline N-oxide and aurachin C110, does not displace ubiquinone-8 from the QH site | Escherichia coli |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
membrane | cytochrome bo3 is the major respiratory oxidase located in the cytoplasmic membrane of Escherichia coli when grown under high oxygen tension | Escherichia coli | 16020 | - |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Fe2+ | heme iron | Escherichia coli |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
2 ubiquinol + O2 | Escherichia coli | - |
2 ubiquinone + 2 H2O | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Escherichia coli | - |
- |
- |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
2 ubiquinol + O2 | - |
Escherichia coli | 2 ubiquinone + 2 H2O | - |
? | |
2 ubiquinol-8 + O2 | the quinone bound at the QH site can form a stable semiquinone. The tightly bound ubiquinone-8 at the QH site is not displaced by ubiquinol-1 even during enzyme turnover | Escherichia coli | 2 ubiquinone-8 + 2 H2O | - |
? | |
additional information | two assay methods: a coupled assay with rat liver DT-diaphorase and NADH as the reductant, and a direct assay using a oxygen electrode, overview | Escherichia coli | ? | - |
? |
Synonyms | Comment | Organism |
---|---|---|
cytochrome bo3 | - |
Escherichia coli |
cytochrome bo3 ubiquinol oxidase | - |
Escherichia coli |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
37 | - |
assay at | Escherichia coli |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7 | - |
assay at | Escherichia coli |
Ki Value [mM] | Ki Value maximum [mM] | Inhibitor | Comment | Organism | Structure |
---|---|---|---|---|---|
0.000015 | - |
aurachin C1-10 | pH 7.0, 37°C, wild-type enzyme | Escherichia coli | |
0.000074 | - |
2-heptyl-4-hydroxyquinoline N-oxide | pH 7.0, 37°C, wild-type enzyme | Escherichia coli |
General Information | Comment | Organism |
---|---|---|
additional information | analysis of a one-site Q-site model and a two-site Q-site model, overview | Escherichia coli |
physiological function | cytochrome bo3 oxidase catalyzes the 2-electron oxidation of ubiquinol-8 and the 4-electron reduction of dioxygen to water | Escherichia coli |