AADAT

Existing Annotations Review

GO Term	Evidence	Action	Reason
GO:0005739 mitochondrion	IBA GO_REF:0000033	ACCEPT	Summary: Phylogenetic (IBA) inference that AADAT is active in the mitochondrion. This is consistent with the UniProt subcellular location call, which is based on the N-terminal mitochondrial transit peptide, and with high-confidence mitochondrial proteome data. Accept as a core localization. Supporting Evidence: file:human/AADAT/AADAT-uniprot.txt SUBCELLULAR LOCATION: Mitochondrion
GO:0016212 L-kynurenine:2-oxoglutarate transaminase activity	IBA GO_REF:0000033	ACCEPT	Summary: Phylogenetic (IBA) inference of kynurenine:2-oxoglutarate transaminase (KAT II) activity. This is a core molecular function, directly supported by experimental data (crystal structure with kynurenine and enzyme assays). Accept. Supporting Evidence: PMID:18056995 Human kynurenine aminotransferase II (hKAT-II) efficiently catalyzes the
GO:0005739 mitochondrion	IEA GO_REF:0000044	ACCEPT	Summary: Electronic annotation of mitochondrial location from UniProt Subcellular Location mapping. Consistent with the transit-peptide-based UniProt call and IBA/HTP evidence. Accept as core. Supporting Evidence: file:human/AADAT/AADAT-uniprot.txt SUBCELLULAR LOCATION: Mitochondrion
GO:0005759 mitochondrial matrix	IEA GO_REF:0000117	ACCEPT	Summary: ARBA electronic annotation to mitochondrial matrix. This more specific compartment is consistent with the Reactome placement of AADAT reactions in the mitochondrial matrix and with the soluble/matrix nature of this transaminase. Accept.
GO:0008483 transaminase activity	IEA GO_REF:0000002	TOO GENERAL	Summary: InterPro2GO electronic annotation to the generic parent term transaminase activity. Correct but uninformative given that specific transaminase activities (aminoadipate and kynurenine transaminase) are experimentally established for this gene, so the specific terms replace it. Reason: Transaminase activity is correct but too general: AADAT has two experimentally established specific transaminase activities, and the generic parent says less than either. Both specific terms (GO:0047536, GO:0016212) are already asserted in this review, so together they cover everything the parent says.
GO:0016212 L-kynurenine:2-oxoglutarate transaminase activity	IEA GO_REF:0000120	ACCEPT	Summary: Electronic (Rhea/EC-based) annotation of kynurenine:2-oxoglutarate transaminase activity, redundant with the experimental IDA/EXP annotations to the same term. Accept; this is a core function.
GO:0030170 pyridoxal phosphate binding	IEA GO_REF:0000002	ACCEPT	Summary: InterPro2GO electronic annotation of PLP binding. AADAT is an obligate PLP-dependent (fold-type I) aminotransferase; PLP forms an internal Schiff base with Lys263 and is the essential cofactor established by structural and cofactor studies. Accept as a core molecular function. Supporting Evidence: PMID:18056995 hKAT-II reveals that it belongs to the fold-type I pyridoxal 5-phosphate
GO:0047313 aromatic-amino-acid:glyoxylate transaminase activity	IEA GO_REF:0000116	KEEP AS NON CORE	Summary: Rhea-based electronic annotation covering glyoxylate-linked transamination of aromatic amino acids (tyrosine, phenylalanine, tryptophan). These are real in vitro activities arising from the very broad active site, but use glyoxylate as an artificial/low-affinity acceptor and are not the principal physiological function. Keep as non-core. Supporting Evidence: PMID:18620547 very broad substrate specificity, is
GO:0047315 L-kynurenine:glyoxylate transaminase activity	IEA GO_REF:0000120	KEEP AS NON CORE	Summary: Electronic annotation of kynurenine:glyoxylate transaminase activity, redundant with the experimental IDA to the same term. A genuine broad-specificity activity using glyoxylate as amino-group acceptor, secondary to the physiological kynurenine:2-oxoglutarate reaction. Keep as non-core.
GO:0047536 L-2-aminoadipate:2-oxoglutarate transaminase activity	IEA GO_REF:0000120	ACCEPT	Summary: Electronic (Rhea/EC 2.6.1.39) annotation of 2-aminoadipate:2-oxoglutarate transaminase activity, redundant with the experimental EXP/IDA annotations to the same term. This is a core function (lysine degradation). Accept.
GO:0047958 glycine:2-oxoglutarate transaminase activity	IEA GO_REF:0000120	KEEP AS NON CORE	Summary: Electronic annotation of glycine:2-oxoglutarate transaminase activity (EC 2.6.1.4). A genuine in vitro broad-specificity activity (also captured by an experimental IDA), but glyoxylate/glycine transamination is a secondary reaction rather than the principal physiological function. Keep as non-core.
GO:0050094 L-methionine:glyoxylate transaminase activity	IEA GO_REF:0000120	KEEP AS NON CORE	Summary: Electronic annotation of methionine:glyoxylate transaminase activity (EC 2.6.1.73), redundant with the experimental IDA to the same term. Methionine is an efficient amino-group donor, but the glyoxylate-acceptor reaction is a broad-specificity activity secondary to the aminoadipate and kynurenine reactions. Keep as non-core.
GO:0005829 cytosol	TAS Reactome:R-HSA-9972889	KEEP AS NON CORE	Summary: Reactome traceable annotation placing an AADAT activity (3-hydroxykynurenine to xanthurenate) in the cytosol; the cytosolic localization of human AADAT is inferred from rat work. A cytosolic pool is reported in the literature (KAT II described as soluble cytoplasmic), but the UniProt-authoritative core call is mitochondrion/matrix. Keep as non-core.
GO:0016212 L-kynurenine:2-oxoglutarate transaminase activity	EXP PMID:18056995 Crystal structure of human kynurenine aminotransferase II.	ACCEPT	Summary: Experimental (EXP) annotation of kynurenine:2-oxoglutarate transaminase (KAT II) activity, supported by the crystal structure of human KAT II in complex with kynurenine and by direct enzyme assays converting kynurenine to kynurenic acid. This is a core molecular function. Accept. Supporting Evidence: PMID:18056995 Human kynurenine aminotransferase II (hKAT-II) efficiently catalyzes the
GO:0047536 L-2-aminoadipate:2-oxoglutarate transaminase activity	EXP PMID:12126930 Characterization of the human gene encoding alpha-aminoadipa...	ACCEPT	Summary: Experimental (EXP) annotation of 2-aminoadipate aminotransferase activity. Bacterial expression of the human AADAT gene confirmed the enzyme activity, and this reaction is an intermediate step in lysine degradation. This is a core molecular function. Accept. Supporting Evidence: PMID:12126930 Bacterial expression studies confirm that the gene encodes for AADAT activity.
GO:0005739 mitochondrion	HTP PMID:34800366 Quantitative high-confidence human mitochondrial proteome an...	ACCEPT	Summary: High-throughput (HTP) mitochondrial-proteome evidence that AADAT localizes to the mitochondrion. Consistent with the transit-peptide-based UniProt call. Accept as core. Supporting Evidence: PMID:34800366 Quantitative high-confidence human mitochondrial proteome
GO:0047315 L-kynurenine:glyoxylate transaminase activity	IDA PMID:18620547 Substrate specificity and structure of human aminoadipate am...	KEEP AS NON CORE	Summary: Direct assay (IDA) of kynurenine:glyoxylate transaminase activity from the broad-specificity substrate screen (glyoxylate used as amino-group acceptor). A genuine in vitro activity, but the physiological kynurenine reaction uses 2-oxoglutarate; glyoxylate is a low-affinity acceptor. Keep as non-core. Supporting Evidence: PMID:18620547 could utilize all 16 tested alpha-oxo acids
GO:0047958 glycine:2-oxoglutarate transaminase activity	IDA PMID:18620547 Substrate specificity and structure of human aminoadipate am...	KEEP AS NON CORE	Summary: Direct assay (IDA) of glycine:2-oxoglutarate transaminase activity, part of the broad substrate profile of KAT II/AADAT. A real in vitro activity but a secondary, non-physiological reaction relative to the aminoadipate and kynurenine functions. Keep as non-core. Supporting Evidence: PMID:18620547 very broad substrate specificity, is
GO:0050094 L-methionine:glyoxylate transaminase activity	IDA PMID:18620547 Substrate specificity and structure of human aminoadipate am...	KEEP AS NON CORE	Summary: Direct assay (IDA) of methionine:glyoxylate transaminase activity. Methionine is one of the efficient amino-group donors of KAT II, but the glyoxylate-acceptor reaction is a broad-specificity in vitro activity secondary to the aminoadipate and kynurenine reactions. Keep as non-core. Supporting Evidence: PMID:18620547 aminoadipate, kynurenine, methionine and glutamate
GO:0005759 mitochondrial matrix	TAS Reactome:R-HSA-508561	ACCEPT	Summary: Reactome traceable annotation placing the aminoadipate/2-oxoglutarate transaminase reaction of AADAT in the mitochondrial matrix. Consistent with the transit peptide and UniProt location. Accept as core compartment.
GO:0005759 mitochondrial matrix	TAS Reactome:R-HSA-70952	ACCEPT	Summary: Reactome traceable annotation (reverse aminoadipate reaction) placing AADAT in the mitochondrial matrix. Same compartment call as above; accept as core.
GO:0005759 mitochondrial matrix	TAS Reactome:R-HSA-893583	ACCEPT	Summary: Reactome traceable annotation (kynurenine + 2-oxoglutarate reaction) placing AADAT in the mitochondrial matrix. Consistent with the UniProt location; accept as core.
GO:0016212 L-kynurenine:2-oxoglutarate transaminase activity	IDA PMID:18620547 Substrate specificity and structure of human aminoadipate am...	ACCEPT	Summary: Direct assay (IDA) of kynurenine:2-oxoglutarate transaminase (KAT II) activity from the systematic substrate/kinetic study. This is a core molecular function of AADAT (kynurenic acid biosynthesis). Accept. Supporting Evidence: PMID:18620547 is a primary enzyme in the brain for
GO:0047536 L-2-aminoadipate:2-oxoglutarate transaminase activity	IDA PMID:18620547 Substrate specificity and structure of human aminoadipate am...	ACCEPT	Summary: Direct assay (IDA) of 2-aminoadipate:2-oxoglutarate transaminase activity. Kinetics show aminoadipate is the best amino-acid substrate (Km 0.9 mM) and the reaction favors the degradative direction (lysine catabolism). This is a core molecular function. Accept. Supporting Evidence: PMID:18620547 the affinity of hKAT II for aminoadipate (Km = 0.9 mM) is much greater than its
GO:0019477 L-lysine catabolic process	IDA	NEW	Summary: Proposed new biological-process annotation. GOA lacks an explicit lysine-catabolism process term for human AADAT, yet the 2-aminoadipate aminotransferase reaction is a committed intermediate step of L-lysine degradation via the saccharopine/aminoadipate pathway (also captured by the UniProt UniPathway annotation to the obsolete GO:0033512). Proposing the current valid term GO:0019477. Supporting Evidence: PMID:18620547 one of the reactions involved in lysine degradation PMID:12126930 an intermediate step in lysine
GO:0034276 kynurenic acid biosynthetic process	IDA	NEW	Summary: Proposed new biological-process annotation. AADAT (KAT II) is a principal enzyme for kynurenic acid (KYNA) synthesis via kynurenine transamination; the process context is not captured in GOA. Proposing GO:0034276 (kynurenic acid biosynthetic process), the committed step of the neuroactive KYNA branch of the tryptophan/ kynurenine pathway. Supporting Evidence: PMID:18056995 transamination of knunrenine to kynurenic acid (KYNA)

Gene Description

Existing Annotations Review

Core Functions

2-aminoadipate aminotransferase activity: transaminates L-2-aminoadipate with 2-oxoglutarate to 2-oxoadipate and L-glutamate, an intermediate step in L-lysine degradation via the saccharopine/aminoadipate pathway.

Kynurenine aminotransferase II activity: transaminates L-kynurenine with 2-oxoglutarate to kynurenate (kynurenic acid) and L-glutamate, the committed step of kynurenic acid biosynthesis in the tryptophan/kynurenine pathway.

Pyridoxal 5'-phosphate binding: PLP is the obligate cofactor of this fold-type I aminotransferase, forming an internal Schiff base with the active-site lysine (Lys263).

References

📚 Additional Documentation

Notes

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