Cloned (Comment) | Organism |
---|---|
N-terminally YFP-tagged enzyme expression and coexpression with a cyan fluorescent protein (CFP) fusion of PTS1, known to mediate localization to peroxisomes, in Nicotiana benthamiana leaves. GOX3 can rescue the cyb2 lethal phenotype in Saccharomyces cerevisiae | Arabidopsis thaliana |
Protein Variants | Comment | Organism |
---|---|---|
additional information | enzyme knockout by construction of three T-DNA insertion lines for GOX3, gox3-1 (GK_523D09), gox3-2 (SALK_020909), and gox3-3 (SAIL_1156_F03), with insertions in exon 10, intron 10, and the 5' untranslated region, respectively. Neither the GOX3 loss-of-function mutants nor the overexpression lines showed phenotypical differences when compared with the wild type in standard growth conditions in both long- and short-day photoperiods. Loss of function of GOX3 induces metabolic rearrangements in roots that mirror wild-type responses under hypoxia. Conditional phenotype of gox3 mutant plants and complementation, overview | Arabidopsis thaliana |
additional information | enzyme-deficient mutant cells can be complementated by expression of GOX3, a glycolate oxidase from Arabdiospsis thaliana, which is capable to synthesize L-lactate from pyruvate, overview | Saccharomyces cerevisiae |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.153 | - |
(S)-lactate | pH 7.5, 25°C | Arabidopsis thaliana |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
mitochondrial intermembrane space | - |
Saccharomyces cerevisiae | 5758 | - |
peroxisome | the enzyme contains a canonical peroxisomal targeting signal | Arabidopsis thaliana | 5777 | - |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
(S)-lactate + 2 ferricytochrome c | Saccharomyces cerevisiae | - |
pyruvate + 2 ferrocytochrome c + 2 H+ | - |
? | |
pyruvate + 2 ferrocytochrome c + 2 H+ | Arabidopsis thaliana | - |
(S)-lactate + 2 ferricytochrome c | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Arabidopsis thaliana | - |
- |
- |
Saccharomyces cerevisiae | - |
- |
- |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
leaf | of mature (6-week-old) plants, not in young rosettes. GOX3 transcript accumulates continuously during dark-induced senescence, reaching a maximum 10 d after transfer to darkness | Arabidopsis thaliana | - |
root | - |
Arabidopsis thaliana | - |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
(S)-lactate + 2 ferricytochrome c | - |
Saccharomyces cerevisiae | pyruvate + 2 ferrocytochrome c + 2 H+ | - |
? | |
additional information | GOX3 shows a broad substrate spectrum, with activity toward a range of L-2-hydroxy acids. glycolate oxidase GOX3 uses L-lactate with a similar efficiency to glycolate. No activity with D-lactate | Arabidopsis thaliana | ? | - |
? | |
pyruvate + 2 ferrocytochrome c + 2 H+ | - |
Arabidopsis thaliana | (S)-lactate + 2 ferricytochrome c | - |
? |
Subunits | Comment | Organism |
---|---|---|
? | x * 45000, SDS-PAGE | Arabidopsis thaliana |
Synonyms | Comment | Organism |
---|---|---|
Cyb2 | - |
Saccharomyces cerevisiae |
L-lactate cytochrome c oxidoreductase | - |
Saccharomyces cerevisiae |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
14.18 | - |
(S)-lactate | pH 7.5, 25°C | Arabidopsis thaliana |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
FMN | prosthetic group | Arabidopsis thaliana | |
heme | - |
Saccharomyces cerevisiae | |
additional information | the enzyme lacks a heme-binding domain and the cytochrome c-binding domain | Arabidopsis thaliana |
General Information | Comment | Organism |
---|---|---|
evolution | the catalytic domains of GOX3 and CYB2, the yeast L-lactate cytochrome c oxidoreductase, are homologous (40% identity and 57% similarity) | Arabidopsis thaliana |
additional information | of the three glycolate oxidases in Arabidopsis thaliana, only GOX3 can efficiently metabolize L-lactate at low intracellular concentrations | Arabidopsis thaliana |
physiological function | glycolate oxidase3, a glycolate oxidase homolog of yeast L-lactate cytochrome c oxidoreductase, supports L-lactate oxidation in roots of Arabidopsis thaliana | Saccharomyces cerevisiae |
physiological function | in roots of Arabidopsis thaliana, L-lactate is generated by the reduction of pyruvate via L-lactate dehydrogenase, EC 1.1.1.27, but this enzyme does not efficiently catalyze the reverse reaction. Glycolate oxidase GOX3 is the enzyme that metabolizes L-lactate to pyruvate in vivo and may ensure the sustainment of low levels of L-lactate after its formation under normoxia. GOX3 does not display activity with natural electron acceptors such as cytochrome c, NAD+, or NADP+ suggests that it does not act as dehydrogenases in vivo. GOX3 plays a more prominent role in heterotrophic tissue than in autotrophic tissues. Enzyme GOX3 can rescue the cyb2 lethal phenotype in Saccharomyces cerevisiae. Possible involvement of GOX3 in controlling L-lactate homeostasis in roots | Arabidopsis thaliana |
kcat/KM Value [1/mMs-1] | kcat/KM Value Maximum [1/mMs-1] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
74.1 | - |
(S)-lactate | pH 7.5, 25°C | Arabidopsis thaliana |