Crystallization (Comment) | Organism |
---|---|
trypanosomal alternative oxidase in the absence and presence of ascofuranone and ascofuranone derivative 5-chloro-3-[(2E,6E)-8-hydroxy-3,7-dimethylnona-2,6-dienyl]-2,4-dihydroxy-6-methylbenzaldehyde, the reservoir solution contains using 28-34% w/v PEG 400, 100 mM imidazole buffer (pH 7.4), and 500 mM potassium formate, X-ray diffraction structure determination and analysis, single-wavelength anomalous dispersion method, anomalous scattering effects caused by Fe measured to 3.2 A resolution | Trypanosoma brucei |
Protein Variants | Comment | Organism |
---|---|---|
A216L | site-directed mutagenesis, the mutation results in almost complete loss of ubiquinol oxidizing activity | Trypanosoma brucei |
A216N | site-directed mutagenesis, the mutation results in almost complete loss of ubiquinol oxidizing activity | Trypanosoma brucei |
E213A | site-directed mutagenesis, the mutation results in almost complete loss of ubiquinol oxidizing activity | Trypanosoma brucei |
E215A | site-directed mutagenesis, the mutation results in almost complete loss of ubiquinol oxidizing activity | Trypanosoma brucei |
L122A | site-directed mutagenesis, the mutation results in almost complete loss of ubiquinol oxidizing activity | Trypanosoma brucei |
L122N | site-directed mutagenesis, the mutation results in almost complete loss of ubiquinol oxidizing activity | Trypanosoma brucei |
R118A | site-directed mutagenesis, the mutation results in almost complete loss of ubiquinol oxidizing activity | Trypanosoma brucei |
R118Q | site-directed mutagenesis, the mutation results in almost complete loss of ubiquinol oxidizing activity | Trypanosoma brucei |
T219V | site-directed mutagenesis, the mutation results in almost complete loss of ubiquinol oxidizing activity | Trypanosoma brucei |
Y220F | site-directed mutagenesis, the mutation results in almost complete loss of ubiquinol oxidizing activity | Trypanosoma brucei |
Y246A | site-directed mutagenesis, the mutant shows reduced activity compared to the wild-type enzyme | Trypanosoma brucei |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
5-chloro-3-[(2E)-3,7-dimethylocta-2,6-dienyl]-2,4-dihydroxy-6-methylbenzaldehyde | an ascofuranone derivative | Trypanosoma brucei | |
5-chloro-3-[(2E,6E)-8-hydroxy-3,7-dimethylnona-2,6-dienyl]-2,4-dihydroxy-6-methylbenzaldehyde | an ascofuranone derivative | Trypanosoma brucei | |
ascofuranone | an antibiotic | Trypanosoma brucei | |
additional information | inhibitor binding induces the ligation of a histidine residue in the active site, inhibitor binding site and structures, overview | Trypanosoma brucei |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Fe2+ | the enzyme is a diiron carboxylate protein, the nonheme diiron carboxylate active site is buried within a four-helix bundle. The structure of the diiron active site was refined as an oxidized Fe(III)-Fe(III) form with a single hydroxo-bridge | Trypanosoma brucei |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
2 ubiquinol + O2 | Trypanosoma brucei | - |
2 ubiquinone + 2 H2O | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Trypanosoma brucei | Q26710 | - |
- |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
2 ubiquinol + O2 | - |
Trypanosoma brucei | 2 ubiquinone + 2 H2O | - |
? | |
2 ubiquinol + O2 | ubiquinol binding model, overview. During the sequential electron reduction process, following the activation of oxygen, free radicals are generated on a tightly bound ubiquinol and Tyr220 | Trypanosoma brucei | 2 ubiquinone + 2 H2O | - |
? |
Subunits | Comment | Organism |
---|---|---|
homodimer | with two hydrophobic cavities per monomer. Both cavities bind ubiquinol and along with Tyr220 are required for the catalytic cycle for O2 reduction, but also inhibitors bind to one cavity and Tyr220, respectively. A second cavity interacts with the inhibitor-bindingcavity at the diiron center | Trypanosoma brucei |
Synonyms | Comment | Organism |
---|---|---|
AOX | - |
Trypanosoma brucei |
cyanide-insensitive alternative oxidase | - |
Trypanosoma brucei |
TAO | - |
Trypanosoma brucei |
trypanosomal alternative oxidase | - |
Trypanosoma brucei |
IC50 Value | IC50 Value Maximum | Comment | Organism | Inhibitor | Structure |
---|---|---|---|---|---|
0.00000048 | - |
pH and temperature not specified in the publication | Trypanosoma brucei | 5-chloro-3-[(2E,6E)-8-hydroxy-3,7-dimethylnona-2,6-dienyl]-2,4-dihydroxy-6-methylbenzaldehyde |
General Information | Comment | Organism |
---|---|---|
additional information | putative ubiquinol binding cavities, overview. The nonheme diiron carboxylate active site is buried within a four-helix bundle. The active site is ligated solely by four glutamate residues in its oxidized inhibitor-free state. Highly conserved Tyr220 iswithin 4 A of the active site and is critical for catalytic activity. The enzyme is a homodimer with two hydrophobic cavities per monomer. Both cavities bind ubiquinol and along with Tyr220 are required for the catalytic cycle for O2 reduction, but also inhibitors bind to one cavity and Tyr220, respectively. A second cavity interacts with the inhibitor-binding cavity at the diiron center. The active site, which is located in a hydrophobic environment deep inside the enzyme molecule, is composed of the diiron center and four glutamate (E123, E162, E213, and E266) and two histidine residues (H165 and H269), all of which are completely conserved | Trypanosoma brucei |
physiological function | AOX is a diiron carboxylate protein that catalyzes the four-electron reduction of dioxygen to water by ubiquinol. AOX plays a critical role in the survival of the parasite in its bloodstream form | Trypanosoma brucei |