Activating Compound | Comment | Organism | Structure |
---|---|---|---|
Thioredoxin f | the enzyme is redox activated by thioredoxin f through the reduction of a disulphide bridge involving Cys153 and Cys173 | Pisum sativum |
Cloned (Comment) | Organism |
---|---|
gene FBP | Pisum sativum |
Protein Variants | Comment | Organism |
---|---|---|
C153S | site-directed mutagenesis | Pisum sativum |
C173S/C178S | site-directed mutagenesis | Pisum sativum |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
additional information | cFBP1 is quite sensitive to higher oxidant concentrations | Pisum sativum | |
S-nitrosoglutathione | GSNO, the chloroplast FBPase isoform cFBP1 is efficiently S-nitrosylated in vitro. GSNO inhibits the FBPase activity in the mutant C173S/C178S but not in mutant C153S. 0.02 mM GSNO produces a 75% activity inhibition in the mutant C173S/C178S, compared with the nontreated protein, S-nitrosylation of FBPase mutants in the Cys of the redox regulatory domain | Pisum sativum |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.11 | - |
D-fructose 1,6-bisphosphate | pH 8.0, 26-27°C, recombinant nontreated mutant C173S/C178S | Pisum sativum | |
0.3 | - |
D-fructose 1,6-bisphosphate | pH 8.0, 26-27°C, recombinant S-nitrosoglutathione-treated mutant C173S/C178S | Pisum sativum |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
chloroplast | - |
Pisum sativum | 9507 | - |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Mg2+ | required for catalysis | Pisum sativum |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
D-fructose 1,6-bisphosphate + H2O | Pisum sativum | - |
D-fructose 6-phosphate + phosphate | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Pisum sativum | P46275 | - |
- |
Oxidation Stability | Organism |
---|---|
cFBP1 is quite sensitive to higher oxidant concentrations. Almost complete oxidation 2 h after S-nitrosoglutathione, GSNO, incubation. GSNO incubation leads to the formation of the regulatory disulphide Cys153-Cys173. H2O2 and oxidized glutathione do not lead to enzyme oxidation | Pisum sativum |
Posttranslational Modification | Comment | Organism |
---|---|---|
additional information | the Pisum sativum cFBP1 isozyme from chloroplasts can be efficiently S-nitrosylated by S-nitrosoglutathione (GSNO) and S-nitroso-N-acetyl-D,L-penicillamine, triggering the formation of the regulatory disulfide. Cys153 S-nitrosylation induces FBPase oxidation in a GSNO concentration manner | Pisum sativum |
nitrosylation | the enzyme (cFBP1) can be efficiently S-nitrosylated by S-nitrosoglutathione and S-nitroso-N-acetyl-D,L-penicillamine, triggering the formation of the regulatory disulphide. S-nitrosylation only occurs during the light period | Pisum sativum |
Purification (Comment) | Organism |
---|---|
- |
Pisum sativum |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
leaf | - |
Pisum sativum | - |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
D-fructose 1,6-bisphosphate + H2O | - |
Pisum sativum | D-fructose 6-phosphate + phosphate | - |
? |
Subunits | Comment | Organism |
---|---|---|
homotetramer | - |
Pisum sativum |
Synonyms | Comment | Organism |
---|---|---|
cFBP1 | - |
Pisum sativum |
cFBP1 | Calvin-Benson cycle fructose-1,6-bisphosphatase isoform | Pisum sativum |
Fbp | - |
Pisum sativum |
FBPase | - |
Pisum sativum |
fructose-1,6-bisphosphatase | - |
Pisum sativum |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
26 | 27 | assay at, room temperature | Pisum sativum |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
8 | - |
assay at | Pisum sativum |
General Information | Comment | Organism |
---|---|---|
evolution | FBPases are homotetrameric enzymes with three different isoforms present in plants, two in chloroplasts (cFBP1 and cFBP2) and one in the cytosol (cyFBP). Only cFBP1 needs to be redox activated in order to be fully active, whilst cFBP2 is not redox regulated and, despite its activity, resists higher oxidant concentrations than cFBP1 | Pisum sativum |
metabolism | fructose-1,6-bisphosphatase (FBPase) is the key enzyme in the Calvin-Benson cycle (CBC). The enzyme is involved in redox regulation in chloroplasts, model of the redox regulation, overview | Pisum sativum |
metabolism | the enzyme belongs to the Calvin-Benson cycle | Pisum sativum |
additional information | redox pattern displayed by cFBP1, overview | Pisum sativum |
physiological function | the Calvin-Benson cycle (CBC) fructose-1,6-bisphosphatase (FBPase) isoform is well known to be redox activated by thioredoxin f through the reduction of a disulfide bridge involving Cys153 and Cys173. cFBP1 needs to be redox activated in order to be fully active | Pisum sativum |