Cloned (Comment) | Organism |
---|---|
expressed in Escherichia coli | Arabidopsis thaliana |
recombinant expression of GFP-tagged HPR2 in transgenic Arabidospsis thaliana plants | Arabidopsis thaliana |
Protein Variants | Comment | Organism |
---|---|---|
additional information | construction of hpr1 knockout and hpr2 knockout. Deletion of HPR2 results in elevated levels of hydroxypyruvate and other metabolites in leaves, photosynthetic gas exchange is slightly altered, especially under long-day conditions. Deletion of HPR1 does not show a severe phenotype, overview. The combined deletion of HPR1 and HPR2 is detrimental to air-grown mutants and alters steady state metabolite profiles, phenotypes, overview. The most prominent naturally occuring mutation causes the decrease in Ala content coupled with enhanced levels of Arg, Asn, and Asp in the hpr1 mutant and the double knockout plant | Arabidopsis thaliana |
additional information | HPR1 knockout plants show slight visually noticeable impairments in air. Under shorter daylengths of 8 h, somewhat slower growth of the hpr1 mutants than of the wild-type, in combination with an approximately 4-week delay in bolting. Combined deletion of both HPR1 and HPR2 (EC 1.1.1.81) results in distinct air-sensitivity and a dramatic reduction in photosynthetic performance | Arabidopsis thaliana |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
oxalate | strong inhibition of HPR2 | Arabidopsis thaliana |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
cytosol | HPR2 | Arabidopsis thaliana | 5829 | - |
peroxisome | HPR! | Arabidopsis thaliana | 5777 | - |
Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
---|---|---|---|
43200 | - |
x * 43200, HPR2, SDS-PAGE | Arabidopsis thaliana |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
hydroxypyruvate + NAD(P)H + H+ | Arabidopsis thaliana | - |
D-glycerate + NAD(P)+ | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Arabidopsis thaliana | Q9C9W5 | - |
- |
Arabidopsis thaliana | Q9CA90 | HPR2; gene At1g79870 encodes isozyme HPR2 | - |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
leaf | - |
Arabidopsis thaliana | - |
leaf | both HPR1 and HPR2 (EC 1.1.1.81) are the major hydroxypyruvate-reducing enzymes in leaves | Arabidopsis thaliana | - |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
glyoxylate + NAD(P)H + H+ | - |
Arabidopsis thaliana | glycolate + NAD(P)+ | - |
? | |
hydroxypyruvate + NAD(P)H + H+ | - |
Arabidopsis thaliana | D-glycerate + NAD(P)+ | - |
? | |
hydroxypyruvate + NADPH | - |
Arabidopsis thaliana | D-glycerate + NADP+ | - |
? |
Subunits | Comment | Organism |
---|---|---|
? | x * 43200, HPR2, SDS-PAGE | Arabidopsis thaliana |
Synonyms | Comment | Organism |
---|---|---|
HPR1 | - |
Arabidopsis thaliana |
HPR2 | - |
Arabidopsis thaliana |
hydroxypyruvate reductase | - |
Arabidopsis thaliana |
NADPH-dependent hydroxypyruvate reductase | - |
Arabidopsis thaliana |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
NADH | - |
Arabidopsis thaliana | |
NADH | 4fold lower activity with HPR2 compared to NADPH | Arabidopsis thaliana | |
NADPH | preferred cofactor of HPR2 | Arabidopsis thaliana | |
NADPH | shows some reactivity with NADPH | Arabidopsis thaliana |
General Information | Comment | Organism |
---|---|---|
physiological function | deletion of any of the core enzymes of the photorespiratory cycle, one of the major pathways of plant primary metabolism, results in severe air-sensitivity of the respective mutants with the exception of the peroxisomal enzyme hydroxypyruvate reductase, HPR1, due to the existence of a second hydroxypyruvate reductase, HPR2, in the cytosol, overview. The enzyme provides a cytosolic bypass to the photorespiratory core cycle in Arabidopsis thaliana | Arabidopsis thaliana |