Cloned (Comment) | Organism |
---|---|
recombinant expression of NAD-ME1, NAD-ME2, and NAD-MEH | Arabidopsis thaliana |
Protein Variants | Comment | Organism |
---|---|---|
additional information | construction of a chimeric enzyme NAD-ME1q, that is composed of the first 176 amino acid residues of NAD-ME2 and the central and C-terminal sequence of NAD-ME1, NAD-ME1q shows a hyperbolic behaviour for (S)-malate and NAD+. Product-inhibition pattern of NAD-ME1q with the three products supports a sequential ordered mechanism | Arabidopsis thaliana |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
(S)-malate | isozyme NAD-ME2, competitive | Arabidopsis thaliana | |
5'-AMP | isozyme NAD-ME2, competitive versus NAD+, mixed inhibition versus (S)-malate | Arabidopsis thaliana | |
CO2 | chimeric mutant NAD-ME1q, mixed inhibition versus NAD+ and (S)-malate; isozyme NAD-ME2 and chimeric mutant NAD-ME1q, mixed inhibition versus NAD+ and (S)-malate | Arabidopsis thaliana | |
additional information | product inhibition patterns of isozyme NAD-ME2, overview; product inhibition patterns of isozyme NAD-ME2, overview | Arabidopsis thaliana | |
NADH | isozyme NAD-ME2, competitive versus NAD+, mixed inhibition versus (S)-malate. NADH shows competitive and mixed-type inhibition versus NAD+ and (S)-malate with chimeric mutant NAD-ME1q; NADH shows competitive and mixed-type inhibition versus NAD+ and (S)-malate with chimeric mutant NAD-ME1q | Arabidopsis thaliana | |
pyruvate | isozyme NAD-ME2, uncompetitive versus NAD+, mixed inhibition versus (S)-malate. Pyruvate inhibition is uncompetitive with respect to NAD+ and mixed with respect to (S)-malate for the chimeric mutant NAD-ME1q; pyruvate inhibition is uncompetitive with respect to NAD+ and mixed with respect to (S)-malate for the chimeric mutant NAD-ME1q | Arabidopsis thaliana | |
Tartrate | substrate analogue, isozyme NAD-ME2, uncompetitive versus NAD+, competitive versus (S)-malate | Arabidopsis thaliana |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
additional information | - |
additional information | kinetic mechanisms of homodimers NAD-ME1 and NAD-ME2, and of NAD-ME heterodimer NAD-MEH, overview. The first 176 amino acids are associated with the differences observed in the kinetic mechanisms of the enzymes. Activity of NAD-ME1 in the direction of malate decarboxylation shows a hyperbolic response, proposed kinetic model for NAD-ME1. Isozyme NAD-ME2 follows a sequential ordered Bi-Ter mechanism. Kinetic properties and mechanism of chimeric mutant NAD-ME1q, overview | Arabidopsis thaliana | |
additional information | - |
additional information | kinetic mechanisms of homodimers NAD-ME1 and NAD-ME2, and of NAD-ME heterodimer NAD-MEH, overview. The first 176 amino acids are associated with the differences observed in the kinetic mechanisms of the enzymes. Activity of NAD-ME1 in the direction of malate decarboxylation shows a hyperbolic response, proposed kinetic model for NAD-ME1. Kinetic properties and mechanism of chimeric mutant NAD-ME1q, overview | Arabidopsis thaliana | |
1.1 | - |
NAD+ | isozyme NAD-ME2, pH 6.5, temperature not specified in the publication | Arabidopsis thaliana | |
2.6 | - |
(S)-malate | isozyme NAD-ME2, pH 6.5, temperature not specified in the publication | Arabidopsis thaliana |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
mitochondrion | isozyme NAD-ME1 | Arabidopsis thaliana | 5739 | - |
mitochondrion | isozymes NAD-ME1 and NAD-ME2 | Arabidopsis thaliana | 5739 | - |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Mn2+ | activates | Arabidopsis thaliana | |
Mn2+ | activates probably | Arabidopsis thaliana |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
(S)-malate + NAD+ | Arabidopsis thaliana | NAD-ME1, -ME2 and -MEH catalyse the reverse reaction of pyruvate reductive carboxylation with very low catalytic activity, supporting the notion that these isoforms act only in (S)-malate oxidation in plant mitochondria | pyruvate + NADH + H+ + CO2 | - |
ir | |
(S)-malate + NAD+ | Arabidopsis thaliana | NAD-ME1, -ME2 and -MEH catalyse the reverse reaction of pyruvate reductive carboxylation with very low catalytic activity, supporting the notion that these isoforms act only in (S)-malate oxidation in plant mitochondria | pyruvate + NADH + H+ + CO2 | - |
r |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Arabidopsis thaliana | Q8L7K9 | isozyme NAD-ME2 | - |
Arabidopsis thaliana | Q9SIU0 | isozyme NAD-ME1 | - |
Purification (Comment) | Organism |
---|---|
recombinant NAD-ME1, NAD-ME2, and NAD-MEH | Arabidopsis thaliana |
Reaction | Comment | Organism | Reaction ID |
---|---|---|---|
(S)-malate + NAD+ = pyruvate + CO2 + NADH + H+ | isozyme NAD-ME2 and chimeric mutant NAD-ME1q follow a sequential ordered Bi-Ter mechanism, NAD+ being the leading substrate followed by (S)-malate. Hetereodimer NAD-MEH can bind both substrates randomly. Interaction between NAD-ME1 and -ME2 generates a heteromeric isozyme NAD-MEH with a particular kinetic behaviour | Arabidopsis thaliana | |
(S)-malate + NAD+ = pyruvate + CO2 + NADH + H+ | isozyme NAD-ME2 and chimeric mutant NAD-ME1q follow a sequential ordered Bi-Ter mechanism, NAD+ being the leading substrate followed by (S)-malate. Isozyme NAD-ME1 and hetereodimer NAD-MEH can bind both substrates randomly. However, NAD-ME1 shows a preferred route that involves the addition of NAD+ first. interaction between NAD-ME1 and -ME2 generates a heteromeric isozyme NAD-MEH with a particular kinetic behaviour | Arabidopsis thaliana |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
(S)-malate + NAD+ | NAD-ME1, -ME2 and -MEH catalyse the reverse reaction of pyruvate reductive carboxylation with very low catalytic activity, supporting the notion that these isoforms act only in (S)-malate oxidation in plant mitochondria | Arabidopsis thaliana | pyruvate + NADH + H+ + CO2 | - |
ir | |
(S)-malate + NAD+ | NAD-ME1, -ME2 and -MEH catalyse the reverse reaction of pyruvate reductive carboxylation with very low catalytic activity, supporting the notion that these isoforms act only in (S)-malate oxidation in plant mitochondria | Arabidopsis thaliana | pyruvate + NADH + H+ + CO2 | - |
r |
Subunits | Comment | Organism |
---|---|---|
dimer | isozymes NAD-ME1 and NAD-ME2 assemble as homo- and heterodimers, the latter is termed NAD-MEH, in vitro and in vivo. Interaction between NAD-ME1 and -ME2 generates a heteromeric enzyme NAD-MEH with a particular kinetic behaviour | Arabidopsis thaliana |
Synonyms | Comment | Organism |
---|---|---|
NAD-malic enzyme | - |
Arabidopsis thaliana |
NAD-ME1 | - |
Arabidopsis thaliana |
NAD-ME2 | - |
Arabidopsis thaliana |
NAD-MEH | - |
Arabidopsis thaliana |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
46 | - |
NAD+ | isozyme NAD-ME2, pH 6.5, temperature not specified in the publication | Arabidopsis thaliana | |
46 | - |
(S)-malate | isozyme NAD-ME2, pH 6.5, temperature not specified in the publication | Arabidopsis thaliana |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
6.5 | - |
forward reaction, assay at | Arabidopsis thaliana |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
NAD+ | - |
Arabidopsis thaliana |
Ki Value [mM] | Ki Value maximum [mM] | Inhibitor | Comment | Organism | Structure |
---|---|---|---|---|---|
0.041 | - |
NADH | versus (S)-malate, pH 6.5, temperature not specified in the publication, isozyme NAD-ME2 | Arabidopsis thaliana | |
0.15 | - |
NADH | versus NAD+, pH 6.5, temperature not specified in the publication, isozyme NAD-ME2 | Arabidopsis thaliana | |
0.45 | - |
5'-AMP | versus NAD+, pH 6.5, temperature not specified in the publication, isozyme NAD-ME2 | Arabidopsis thaliana | |
0.8 | - |
Tartrate | versus (S)-malate, pH 6.5, temperature not specified in the publication, isozyme NAD-ME2 | Arabidopsis thaliana | |
1.5 | - |
5'-AMP | versus (S)-malate, pH 6.5, temperature not specified in the publication, isozyme NAD-ME2 | Arabidopsis thaliana | |
3 | - |
CO2 | versus NAD+, pH 6.5, temperature not specified in the publication, isozyme NAD-ME2 | Arabidopsis thaliana | |
4 | - |
Tartrate | versus NAD+, pH 6.5, temperature not specified in the publication, isozyme NAD-ME2 | Arabidopsis thaliana | |
7 | - |
CO2 | versus (S)-malate, pH 6.5, temperature not specified in the publication, isozyme NAD-ME2 | Arabidopsis thaliana | |
11 | - |
pyruvate | versus NAD+, pH 6.5, temperature not specified in the publication, isozyme NAD-ME2 | Arabidopsis thaliana | |
14 | - |
pyruvate | versus (S)-malate, pH 6.5, temperature not specified in the publication, isozyme NAD-ME2 | Arabidopsis thaliana |
General Information | Comment | Organism |
---|---|---|
additional information | interaction between NAD-ME1 and -ME2 generates a heteromeric enzyme NAD-MEH with a particular kinetic behaviour. The N-terminal region of NAD-ME1 and -ME2 is associated with the order of substrate binding. The chimeric enzyme NAD-ME1q, that is composed of the first 176 amino acid residues of NAD-ME2 and the central and C-terminal sequence of NAD-ME1, shows a hyperbolic behaviour for (S)-malate and NAD+. Product-inhibition pattern of NAD-ME1q with the three products supports a sequential ordered mechanism | Arabidopsis thaliana |
physiological function | for a metabolic condition in which the mitochondrial NAD level is low and the (S)-malate level is high, the activity of homodimeric isozyme NAD-ME2 and/or heterodimer NAD-MEH would be preferred over that of homodimeric isozyme NAD-ME1 | Arabidopsis thaliana |