Protein Variants | Comment | Organism |
---|---|---|
T335A | nonphosphorylatable variant | Arabidopsis thaliana |
T335D | phosphomimetic variant, exhibits reduced NADH-dependent hydroxypyruvate reductase activity while showing improved NADPH-dependent activity | Arabidopsis thaliana |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.018 | - |
NADH | mutant T335A, pH 6.2, 25°C | Arabidopsis thaliana | |
0.018 | - |
NADH | wild-type, pH 6.2, 25°C | Arabidopsis thaliana | |
0.028 | - |
NADH | mutant T335D, pH 6.2, 25°C | Arabidopsis thaliana | |
0.102 | - |
NADPH | mutant T335D, pH 6.2, 25°C | Arabidopsis thaliana | |
0.135 | - |
NADPH | mutant T335A, pH 6.2, 25°C | Arabidopsis thaliana | |
0.147 | - |
NADPH | wild-type, pH 6.2, 25°C | Arabidopsis thaliana | |
0.167 | - |
Hydroxypyruvate | mutant T335D, cosubstrate NADH, pH 6.2, 25°C | Arabidopsis thaliana | |
0.173 | - |
Hydroxypyruvate | wild-type, cosubstrate NADH, pH 6.2, 25°C | Arabidopsis thaliana | |
0.22 | - |
Hydroxypyruvate | mutant T335A, cosubstrate NADH, pH 6.2, 25°C | Arabidopsis thaliana | |
0.995 | - |
Hydroxypyruvate | mutant T335D, cosubstrate NADPH, pH 6.2, 25°C | Arabidopsis thaliana | |
1.428 | - |
Hydroxypyruvate | wild-type, cosubstrate NADPH, pH 6.2, 25°C | Arabidopsis thaliana | |
1.579 | - |
Hydroxypyruvate | mutant T335A, cosubstrate NADPH, pH 6.2, 25°C | Arabidopsis thaliana |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
peroxisome | - |
Arabidopsis thaliana | 5777 | - |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Arabidopsis thaliana | Q9C9W5 | catalyzes reactions of EC 1.1.1.29 and EC 1.1.1.26 | - |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
leaf | - |
Arabidopsis thaliana | - |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
glyoxylate + NADH + H+ | reaction of EC 1.1.1.26 | Arabidopsis thaliana | glycolate + NAD+ | - |
? | |
hydroxypyruvate + NADH + H+ | - |
Arabidopsis thaliana | D-glycerate + NAD+ | - |
? | |
hydroxypyruvate + NADPH + H+ | NADPH is a poor cofactor for wild-type | Arabidopsis thaliana | D-glycerate + NADP+ | - |
? |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
139 | - |
Hydroxypyruvate | mutant T335D, cosubstrate NADH, pH 6.2, 25°C | Arabidopsis thaliana | |
144 | - |
NADH | mutant T335D, pH 6.2, 25°C | Arabidopsis thaliana | |
148 | - |
NADPH | mutant T335A, pH 6.2, 25°C | Arabidopsis thaliana | |
150 | - |
Hydroxypyruvate | mutant T335A, cosubstrate NADPH, pH 6.2, 25°C | Arabidopsis thaliana | |
160 | - |
Hydroxypyruvate | wild-type, cosubstrate NADPH, pH 6.2, 25°C | Arabidopsis thaliana | |
162 | - |
NADPH | wild-type, pH 6.2, 25°C | Arabidopsis thaliana | |
206 | - |
Hydroxypyruvate | mutant T335D, cosubstrate NADPH, pH 6.2, 25°C | Arabidopsis thaliana | |
218 | - |
NADH | mutant T335A, pH 6.2, 25°C | Arabidopsis thaliana | |
230 | - |
NADPH | mutant T335D, pH 6.2, 25°C | Arabidopsis thaliana | |
248 | - |
NADH | wild-type, pH 6.2, 25°C | Arabidopsis thaliana | |
253 | - |
Hydroxypyruvate | mutant T335A, cosubstrate NADH, pH 6.2, 25°C | Arabidopsis thaliana | |
284 | - |
Hydroxypyruvate | wild-type, cosubstrate NADH, pH 6.2, 25°C | Arabidopsis thaliana |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
NADH | - |
Arabidopsis thaliana | |
NADPH | NADPH is a poor cofactor for wild-type | Arabidopsis thaliana |
General Information | Comment | Organism |
---|---|---|
metabolism | HPR1 phosphomimetic variant T335D exhibits reduced NADH-dependent hydroxypyruvate reductase activity but improved NADPH-dependent activity. Complementation of the Arabidopsis HPR1 mutant by either wild-type HPR1 or HPR1 nonphosphorylatable mutant T335A fully complements the photorespiratory growth phenotype of the HPR1 mutant in ambient air, whereas HPR1 T335D-containing HPR1 mutant plants remain smaller and have lower photosynthetic CO2 assimilation rates. These phenotypes were associated with subtle perturbations in the photorespiratory cycle of HPR1 T335D-complemented HPR1 mutant rosettes compared to all other HPR1-containing lines | Arabidopsis thaliana |