At1g14810 encodes the Arabidopsis aspartate-semialdehyde dehydrogenase, a homodimeric enzyme detected in the chloroplast stroma. It uses NADPH to reduce aspartyl phosphate to aspartate semialdehyde, providing the common intermediate for the diaminopimelate lysine branch and for homoserine-derived threonine and methionine synthesis. Purified recombinant enzyme exhibits cooperative dependence on aspartyl phosphate. The experimentally demonstrated NADPH reaction does not establish an equivalent native NADH-dependent route.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0004073 aspartate-semialdehyde dehydrogenase (NADP+) activity | IBA GO_REF:0000033 | ACCEPT | Summary: Purified plant ASDH reduces aspartyl phosphate using NADPH. Reason: Primary PMID:11812229 directly measures NADPH oxidation and cooperative substrate dependence. The assignment to At1g14810 is explicitly corroborated by full PMID:22303247 and curated NCBI Gene:838046. ARBA-only UniProt catalytic prose is not used as evidence. Supporting Evidence: PMID:11812229 The plant enzyme exhibited a specific activity of 26 micromol NADPH oxidized min(-1) mg(-1) of protein with a K(M) value for NADPH of 92 microM. PMID:22303247 In vitro overproduction and analysis of the A. thaliana At1g14810 confirmed the predicted aspartate semialdehyde dehydrogenase activity |
| GO:0004073 aspartate-semialdehyde dehydrogenase (NADP+) activity | IEA GO_REF:0000120 | ACCEPT | Summary: Purified plant ASDH reduces aspartyl phosphate using NADPH. Reason: Primary PMID:11812229 directly measures NADPH oxidation and cooperative substrate dependence. The assignment to At1g14810 is explicitly corroborated by full PMID:22303247 and curated NCBI Gene:838046. ARBA-only UniProt catalytic prose is not used as evidence. Supporting Evidence: PMID:11812229 The plant enzyme exhibited a specific activity of 26 micromol NADPH oxidized min(-1) mg(-1) of protein with a K(M) value for NADPH of 92 microM. PMID:22303247 In vitro overproduction and analysis of the A. thaliana At1g14810 confirmed the predicted aspartate semialdehyde dehydrogenase activity |
| GO:0008652 amino acid biosynthetic process | IEA GO_REF:0000002 | MODIFY | Summary: Use the experimentally supported specific pathway or activity. Reason: ASDH executes the common aspartate-family reduction; primary PMID:11812229 supports NADP-dependent aspartate-semialdehyde dehydrogenase chemistry, and PMID:22303247 places the product at the lysine versus homoserine branch. Proposed replacements: aspartate family amino acid biosynthetic process Supporting Evidence: PMID:11812229 The plant enzyme exhibited a specific activity of 26 micromol NADPH oxidized min(-1) mg(-1) of protein with a K(M) value for NADPH of 92 microM. PMID:22303247 In vitro overproduction and analysis of the A. thaliana At1g14810 confirmed the predicted aspartate semialdehyde dehydrogenase activity |
| GO:0009085 L-lysine biosynthetic process | IBA GO_REF:0000033 | ACCEPT | Summary: ASDH supplies the shared aspartate-family biosynthetic intermediate. Reason: The enzyme catalyzes aspartate-semialdehyde formation upstream of lysine and homoserine; threonine derived from homoserine also supplies the plant isoleucine route. These claims describe shared pathway participation, not exclusive commitment or direct catalysis of the final product-forming step. Supporting Evidence: PMID:11812229 The plant enzyme exhibited a specific activity of 26 micromol NADPH oxidized min(-1) mg(-1) of protein with a K(M) value for NADPH of 92 microM. |
| GO:0009085 L-lysine biosynthetic process | IEA GO_REF:0000002 | ACCEPT | Summary: ASDH supplies the shared aspartate-family biosynthetic intermediate. Reason: The enzyme catalyzes aspartate-semialdehyde formation upstream of lysine and homoserine; threonine derived from homoserine also supplies the plant isoleucine route. These claims describe shared pathway participation, not exclusive commitment or direct catalysis of the final product-forming step. Supporting Evidence: PMID:11812229 The plant enzyme exhibited a specific activity of 26 micromol NADPH oxidized min(-1) mg(-1) of protein with a K(M) value for NADPH of 92 microM. |
| GO:0009088 L-threonine biosynthetic process | IEA GO_REF:0000120 | ACCEPT | Summary: ASDH supplies the shared aspartate-family biosynthetic intermediate. Reason: The enzyme catalyzes aspartate-semialdehyde formation upstream of lysine and homoserine; threonine derived from homoserine also supplies the plant isoleucine route. These claims describe shared pathway participation, not exclusive commitment or direct catalysis of the final product-forming step. Supporting Evidence: PMID:11812229 The plant enzyme exhibited a specific activity of 26 micromol NADPH oxidized min(-1) mg(-1) of protein with a K(M) value for NADPH of 92 microM. |
| GO:0009090 L-homoserine biosynthetic process | IBA GO_REF:0000033 | ACCEPT | Summary: ASDH supplies the shared aspartate-family biosynthetic intermediate. Reason: The enzyme catalyzes aspartate-semialdehyde formation upstream of lysine and homoserine; threonine derived from homoserine also supplies the plant isoleucine route. These claims describe shared pathway participation, not exclusive commitment or direct catalysis of the final product-forming step. Supporting Evidence: PMID:11812229 The plant enzyme exhibited a specific activity of 26 micromol NADPH oxidized min(-1) mg(-1) of protein with a K(M) value for NADPH of 92 microM. |
| GO:0016620 oxidoreductase activity, acting on the aldehyde or oxo group of donors, NAD or NADP as acceptor | IEA GO_REF:0000002 | MODIFY | Summary: Use the experimentally supported specific pathway or activity. Reason: ASDH executes the common aspartate-family reduction; primary PMID:11812229 supports NADP-dependent aspartate-semialdehyde dehydrogenase chemistry, and PMID:22303247 places the product at the lysine versus homoserine branch. Proposed replacements: aspartate-semialdehyde dehydrogenase (NADP+) activity Supporting Evidence: PMID:11812229 The plant enzyme exhibited a specific activity of 26 micromol NADPH oxidized min(-1) mg(-1) of protein with a K(M) value for NADPH of 92 microM. PMID:22303247 In vitro overproduction and analysis of the A. thaliana At1g14810 confirmed the predicted aspartate semialdehyde dehydrogenase activity |
| GO:0046983 protein dimerization activity | IEA GO_REF:0000002 | MODIFY | Summary: Specify the experimentally observed homodimer. Reason: Primary PMID:11812229 reports homodimeric Arabidopsis ASDH with36-kDa subunits, providing evidence beyond the unvetted ARBA assembly text. Proposed replacements: protein homodimerization activity Supporting Evidence: PMID:11812229 ASDH is an homodimeric enzyme composed of subunits of 36 kDa. |
| GO:0050661 NADP binding | IEA GO_REF:0000002 | ACCEPT | Summary: NADP binding is supported by direct NADPH kinetics. Reason: The purified plant enzyme has a measured NADPH Km of92µM. Binding of this redox cofactor is an integral catalytic property, not a peripheral association. Supporting Evidence: PMID:11812229 The plant enzyme exhibited a specific activity of 26 micromol NADPH oxidized min(-1) mg(-1) of protein with a K(M) value for NADPH of 92 microM. |
| GO:0051287 NAD binding | IEA GO_REF:0000002 | UNDECIDED | Summary: Binding of the distinct NAD redox pair remains unresolved. Reason: The available primary PMID:11812229 reports NADPH, not NADH/NAD+ use. The broad NAD-binding fold does not by itself settle phosphate specificity; publisher full text could not be retrieved to check a donor comparison. NADP-supported activity is retained without asserting that NAD binding is absent. Supporting Evidence: |
| GO:1901705 L-isoleucine biosynthetic process | IEA GO_REF:0000002 | ACCEPT | Summary: ASDH supplies the shared aspartate-family biosynthetic intermediate. Reason: The enzyme catalyzes aspartate-semialdehyde formation upstream of lysine and homoserine; threonine derived from homoserine also supplies the plant isoleucine route. These claims describe shared pathway participation, not exclusive commitment or direct catalysis of the final product-forming step. Supporting Evidence: PMID:11812229 The plant enzyme exhibited a specific activity of 26 micromol NADPH oxidized min(-1) mg(-1) of protein with a K(M) value for NADPH of 92 microM. |
| GO:0009570 chloroplast stroma | HDA PMID:18431481 Sorting signals, N-terminal modifications and abundance of t... | NEW | Summary: Native At1g14810 protein is detected in chloroplast stromal preparations. Reason: Primary PMID:18431481 supplemental S1 row 73 identifies At1g14810.1 with 13 observations and assigns plastid stroma. S2 row 299 reports stromal-enrichment abundance and S3 row 41 independently detects it in stromal preparations. The exact locus-matching source rows were inspected and retained with download provenance. No cellular-component annotation exists in the seeded target review; this adds the directly observed compartment, not a new metabolic process or a location inferred solely from pathway membership. Supporting Evidence: file:ARATH/TS1/TS1-source-analysis/localization-table-extraction.json AT1G14810.1 |
Loading supporting content…
Download this section (compressed HTML)Q: What relative NADH and NADPH activities are supported by matched purified-isoform assays and physiological cofactor concentrations?
Experiment: Combine endogenous localization and fraction purity controls with isotope tracing and matched purified-enzyme substrate/cofactor measurements; distinguish shared precursor supply, net flux and secondary developmental or pathogen phenotypes.
Type: compartment-resolved isotope flux and enzyme kinetics
Loading supporting content…
Download this section (compressed HTML)Loading supporting content…
Download this section (compressed HTML)