PAT is a plastid class-Ib aminotransferase that catalyzes both aspartate/2-oxoglutarate transamination and formation of arogenate from prephenate using aspartate or glutamate as amino donor. These pyridoxal-phosphate-dependent activities connect central nitrogen metabolism with the arogenate route of aromatic amino-acid biosynthesis. The gene is also known as AAT or MEE17.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0003824 catalytic activity | IEA GO_REF:0000002 | MODIFY | Summary: Use the directly demonstrated aminotransferase activities. Reason: General catalysis/transamination is correct but less informative than the supported specific reactions. Proposed replacements: L-aspartate:2-oxoglutarate transaminase activity L-aspartate:prephenate transaminase activity L-glutamate:prephenate transaminase activity Supporting Evidence: file:ARATH/PAT/PAT-uniprot.txt Reaction=L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate; |
| GO:0004069 L-aspartate:2-oxoglutarate transaminase activity | IDA PMID:21102469 Prephenate aminotransferase directs plant phenylalanine bios... | ACCEPT | Summary: The enzyme catalyzes aspartate/2-oxoglutarate transamination. Reason: Direct target enzymology supports reversible Asp/Glu interconversion. PMID:20883697 includes purified Arabidopsis PAT and PMID:25070637 / PMID:28011691 verify WT activity; pine results in PMID:16623902 are comparative only. Supporting Evidence: file:ARATH/PAT/PAT-uniprot.txt Reaction=L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate; file:ARATH/PAT/PAT-uniprot.txt Reaction=L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate; |
| GO:0004069 L-aspartate:2-oxoglutarate transaminase activity | IEA GO_REF:0000120 | ACCEPT | Summary: The enzyme catalyzes aspartate/2-oxoglutarate transamination. Reason: Direct target enzymology supports reversible Asp/Glu interconversion. PMID:20883697 includes purified Arabidopsis PAT and PMID:25070637 / PMID:28011691 verify WT activity; pine results in PMID:16623902 are comparative only. Supporting Evidence: file:ARATH/PAT/PAT-uniprot.txt Reaction=L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate; file:ARATH/PAT/PAT-uniprot.txt Reaction=L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate; |
| GO:0005829 cytosol | RCA NOT PMID:21166475 Analysis of the Arabidopsis cytosolic proteome highlights su... | UNDECIDED | Summary: The PAT localization exclusion remains unresolved. Reason: The seeded annotation explicitly excludes cytosolic localization. Plastid/chloroplast targeting of PAT supports its principal organellar location, but does not alone establish absence of a minor or conditional cytosolic pool. The precise target-specific exclusion behind the PMID:21166475 proteomic classification could not be resolved from accessible material. Supporting Evidence: |
| GO:0006520 amino acid metabolic process | IBA GO_REF:0000033 | MODIFY | Summary: Specify the experimentally grounded amino-acid processes. Reason: For ASP2/ASP5 the reversible AspAT reaction directly metabolizes Asp and Glu. PAT additionally catalyzes arogenate formation in phenylalanine biosynthesis; broad precursor supply alone does not establish every downstream pathway. Propagation Review Root cause: TERM SCOPING PROBLEM Failure modes: GRANULARITY MISMATCH Sources checked: PANTHER:PTN002887088 SUPPORTS TRANSFER The proximate PAINT node supports the broad ancestral enzymatic/metabolic claim; direct target biochemistry permits a more specific term. This is refinement, not rejection of inheritance. Proposed replacements: L-phenylalanine biosynthetic process Supporting Evidence: file:ARATH/PAT/PAT-uniprot.txt Reaction=L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate; |
| GO:0006520 amino acid metabolic process | IEA GO_REF:0000002 | MODIFY | Summary: Specify the experimentally grounded amino-acid processes. Reason: For ASP2/ASP5 the reversible AspAT reaction directly metabolizes Asp and Glu. PAT additionally catalyzes arogenate formation in phenylalanine biosynthesis; broad precursor supply alone does not establish every downstream pathway. Proposed replacements: L-phenylalanine biosynthetic process Supporting Evidence: file:ARATH/PAT/PAT-uniprot.txt Reaction=L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate; |
| GO:0008483 transaminase activity | IBA GO_REF:0000033 | MODIFY | Summary: Use the directly demonstrated aminotransferase activities. Reason: General catalysis/transamination is correct but less informative than the supported specific reactions. Propagation Review Root cause: TERM SCOPING PROBLEM Failure modes: GRANULARITY MISMATCH Sources checked: PANTHER:PTN002887088 SUPPORTS TRANSFER The proximate PAINT node supports the broad ancestral enzymatic/metabolic claim; direct target biochemistry permits a more specific term. This is refinement, not rejection of inheritance. Proposed replacements: L-aspartate:2-oxoglutarate transaminase activity L-aspartate:prephenate transaminase activity L-glutamate:prephenate transaminase activity Supporting Evidence: file:ARATH/PAT/PAT-uniprot.txt Reaction=L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate; |
| GO:0008483 transaminase activity | IEA GO_REF:0000002 | MODIFY | Summary: Use the directly demonstrated aminotransferase activities. Reason: General catalysis/transamination is correct but less informative than the supported specific reactions. Proposed replacements: L-aspartate:2-oxoglutarate transaminase activity L-aspartate:prephenate transaminase activity L-glutamate:prephenate transaminase activity Supporting Evidence: file:ARATH/PAT/PAT-uniprot.txt Reaction=L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate; |
| GO:0009094 L-phenylalanine biosynthetic process | IEA GO_REF:0000041 | ACCEPT | Summary: PAT catalyzes the arogenate-forming step of phenylalanine biosynthesis. Reason: The enzyme itself performs the transamination step. Arabidopsis target biochemistry in PMID:20883697 / PMID:21102469 supports participation; petunia and tobacco perturbations are comparative evidence, not relabeled Arabidopsis phenotypes. Supporting Evidence: PMID:21102469 PPA-AT directs carbon flux from prephenate toward arogenate |
| GO:0009507 chloroplast | HDA PMID:18431481 Sorting signals, N-terminal modifications and abundance of t... | ACCEPT | Summary: The enzyme acts in plastids, with chloroplast evidence. Reason: PAT is curated as chloroplast-localized in its own UniProt record. The target-specific chloroplast proteomics annotation (PMID:18431481) and stromal proteomics annotation (PMID:20061580) are consistent with that curated plastid targeting. The chloroplast-stroma annotation is retained as convergent curator-reviewed subplastid proteomic evidence; this does not establish stromule residence. Supporting Evidence: file:ARATH/PAT/PAT-uniprot.txt Plastid, chloroplast |
| GO:0009507 chloroplast | IEA GO_REF:0000044 | ACCEPT | Summary: The enzyme acts in plastids, with chloroplast evidence. Reason: PAT is curated as chloroplast-localized in its own UniProt record. The target-specific chloroplast proteomics annotation (PMID:18431481) and stromal proteomics annotation (PMID:20061580) are consistent with that curated plastid targeting. The chloroplast-stroma annotation is retained as convergent curator-reviewed subplastid proteomic evidence; this does not establish stromule residence. Supporting Evidence: file:ARATH/PAT/PAT-uniprot.txt Plastid, chloroplast |
| GO:0009507 chloroplast | ISM GO_REF:0000122 | ACCEPT | Summary: The enzyme acts in plastids, with chloroplast evidence. Reason: PAT is curated as chloroplast-localized in its own UniProt record. The target-specific chloroplast proteomics annotation (PMID:18431481) and stromal proteomics annotation (PMID:20061580) are consistent with that curated plastid targeting. The chloroplast-stroma annotation is retained as convergent curator-reviewed subplastid proteomic evidence; this does not establish stromule residence. Supporting Evidence: file:ARATH/PAT/PAT-uniprot.txt Plastid, chloroplast |
| GO:0009570 chloroplast stroma | HDA PMID:20061580 AT_CHLORO, a comprehensive chloroplast proteome database wit... | ACCEPT | Summary: The enzyme acts in plastids, with chloroplast evidence. Reason: PAT is curated as chloroplast-localized in its own UniProt record. The target-specific chloroplast proteomics annotation (PMID:18431481) and stromal proteomics annotation (PMID:20061580) are consistent with that curated plastid targeting. The chloroplast-stroma annotation is retained as convergent curator-reviewed subplastid proteomic evidence; this does not establish stromule residence. Supporting Evidence: file:ARATH/PAT/PAT-uniprot.txt Plastid, chloroplast |
| GO:0009793 embryo development ending in seed dormancy | IMP PMID:15634699 Genetic and molecular identification of genes required for f... | KEEP AS NON CORE | Summary: PAT/MEE17 is required for normal early reproductive development. Reason: The PMID:15634699 insertion screen and curated target identification support a contextual developmental role. This does not identify an embryo-specific enzyme activity beyond amino-acid supply. Supporting Evidence: file:ARATH/PAT/PAT-uniprot.txt Required for early |
| GO:0030170 pyridoxal phosphate binding | IEA GO_REF:0000002 | ACCEPT | Summary: Pyridoxal phosphate is the integral catalytic cofactor. Reason: The conserved PLP-dependent aminotransferase mechanism and curated cofactor information support this core binding property. Supporting Evidence: file:ARATH/PAT/PAT-uniprot.txt Name=pyridoxal 5'-phosphate; |
| GO:0033853 L-aspartate:prephenate transaminase activity | IDA PMID:20883697 Identification of a plant gene encoding glutamate/aspartate-... | ACCEPT | Summary: PAT transfers nitrogen to prephenate to form arogenate. Reason: Purified Arabidopsis enzyme characterized in PMID:20883697 uses both aspartate and glutamate donors. This is target-specific activity, distinct from the inactive ASP5 comparator; WT activity is not invalidated by the mutant correction PMID:28011691. Supporting Evidence: PMID:20883697 this activity is housed by the prokaryotic-type plastidic aspartate aminotransferase (At2g22250) |
| GO:0033853 L-aspartate:prephenate transaminase activity | IDA PMID:21102469 Prephenate aminotransferase directs plant phenylalanine bios... | ACCEPT | Summary: PAT transfers nitrogen to prephenate to form arogenate. Reason: Purified Arabidopsis enzyme characterized in PMID:20883697 uses both aspartate and glutamate donors. This is target-specific activity, distinct from the inactive ASP5 comparator; WT activity is not invalidated by the mutant correction PMID:28011691. Supporting Evidence: PMID:20883697 this activity is housed by the prokaryotic-type plastidic aspartate aminotransferase (At2g22250) |
| GO:0033853 L-aspartate:prephenate transaminase activity | IEA GO_REF:0000120 | ACCEPT | Summary: PAT transfers nitrogen to prephenate to form arogenate. Reason: Purified Arabidopsis enzyme characterized in PMID:20883697 uses both aspartate and glutamate donors. This is target-specific activity, distinct from the inactive ASP5 comparator; WT activity is not invalidated by the mutant correction PMID:28011691. Supporting Evidence: PMID:20883697 this activity is housed by the prokaryotic-type plastidic aspartate aminotransferase (At2g22250) |
| GO:0033854 L-glutamate:prephenate transaminase activity | IDA PMID:20883697 Identification of a plant gene encoding glutamate/aspartate-... | ACCEPT | Summary: PAT transfers nitrogen to prephenate to form arogenate. Reason: Purified Arabidopsis enzyme characterized in PMID:20883697 uses both aspartate and glutamate donors. This is target-specific activity, distinct from the inactive ASP5 comparator; WT activity is not invalidated by the mutant correction PMID:28011691. Supporting Evidence: PMID:20883697 this activity is housed by the prokaryotic-type plastidic aspartate aminotransferase (At2g22250) |
| GO:0033854 L-glutamate:prephenate transaminase activity | IDA PMID:21102469 Prephenate aminotransferase directs plant phenylalanine bios... | ACCEPT | Summary: PAT transfers nitrogen to prephenate to form arogenate. Reason: Purified Arabidopsis enzyme characterized in PMID:20883697 uses both aspartate and glutamate donors. This is target-specific activity, distinct from the inactive ASP5 comparator; WT activity is not invalidated by the mutant correction PMID:28011691. Supporting Evidence: PMID:20883697 this activity is housed by the prokaryotic-type plastidic aspartate aminotransferase (At2g22250) |
| GO:0033854 L-glutamate:prephenate transaminase activity | IEA GO_REF:0000120 | ACCEPT | Summary: PAT transfers nitrogen to prephenate to form arogenate. Reason: Purified Arabidopsis enzyme characterized in PMID:20883697 uses both aspartate and glutamate donors. This is target-specific activity, distinct from the inactive ASP5 comparator; WT activity is not invalidated by the mutant correction PMID:28011691. Supporting Evidence: PMID:20883697 this activity is housed by the prokaryotic-type plastidic aspartate aminotransferase (At2g22250) |
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Download this section (compressed HTML)Q: PMID:20883697 identifies native Arabidopsis At2g22250 prephenate aminotransferase, producing arogenate, the shared precursor for phenylalanine and tyrosine. What target-specific physiological evidence and annotation convention support adding a tyrosine-biosynthesis process assignment alongside the existing phenylalanine assignment, without inferring quantitative flux solely from shared precursor chemistry?
Experiment: Compare labeled precursor incorporation into arogenate, phenylalanine and tyrosine in controlled PAT perturbation and complementation, distinguishing aromatic-branch effects from its independently established aspartate aminotransferase activity. A growth phenotype alone would not resolve pathway flux.
Type: native aromatic-amino-acid flux
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