NCGR_LOCUS3088

Existing Annotations Review

GO Term	Evidence	Action	Reason
GO:0036220 ITP diphosphatase activity	IEA GO_REF:0000104	ACCEPT	Summary: Core enzymatic activity of ITPase. Hydrolysis of ITP to IMP and diphosphate is the primary characterized function of the HAM1/ITPA family across all organisms. Well-supported by HAMAP rule MF_03148 and extensive biochemical characterization of orthologs in Arabidopsis [PMID:36464781]. Supporting Evidence: PMID:36464781 Inosine triphosphate pyrophosphatase dephosphorylates deaminated nucleoside di- and triphosphates to the respective monophosphates file:9POAL/NCGR_LOCUS3088/NCGR_LOCUS3088-notes.md HAM1/ITPase family is well-characterized across bacteria, yeast, plants, and mammals
GO:0035870 dITP diphosphatase activity	IEA GO_REF:0000104	ACCEPT	Summary: Core enzymatic activity. HAM1/ITPase family enzymes do not distinguish between deoxy- and ribose forms of non-canonical purines. dITP hydrolysis is essential for preventing deoxyinosine incorporation into DNA [PMID:36464781]. Supporting Evidence: PMID:36464781 an elevated inosine and deoxyinosine content in RNA and DNA, respectively file:9POAL/NCGR_LOCUS3088/NCGR_LOCUS3088-notes.md HAM1/ITPase family is well-characterized across bacteria, yeast, plants, and mammals
GO:0036222 XTP diphosphatase activity	IEA GO_REF:0000104	ACCEPT	Summary: Core enzymatic activity. Hydrolysis of xanthosine 5'-triphosphate is a well-documented activity of the HAM1/ITPase family, supported by HAMAP rule MF_03148 and catalytic activity annotations in UniProt. Supporting Evidence: file:9POAL/NCGR_LOCUS3088/NCGR_LOCUS3088-notes.md HAM1/ITPase family is well-characterized across bacteria, yeast, plants, and mammals
GO:0047429 nucleoside triphosphate diphosphatase activity	IEA GO_REF:0000104	KEEP AS NON CORE	Summary: This is a parent term of the three specific substrate activities (ITP, dITP, XTP diphosphatase). While not incorrect, it is redundant given the more specific annotations are present. Should be kept as non-core since it adds no information beyond what the specific terms provide. Supporting Evidence: file:9POAL/NCGR_LOCUS3088/NCGR_LOCUS3088-notes.md HAM1/ITPase family is well-characterized across bacteria, yeast, plants, and mammals
GO:0046872 metal ion binding	IEA GO_REF:0000104	KEEP AS NON CORE	Summary: ITPase requires Mg2+ or Mn2+ as cofactor (1 per subunit) for catalytic activity. However, metal ion binding is a very generic MF term that provides little functional insight. The metal binding is intrinsic to the catalytic mechanism rather than a distinct function. Supporting Evidence: file:9POAL/NCGR_LOCUS3088/NCGR_LOCUS3088-notes.md HAM1/ITPase family is well-characterized across bacteria, yeast, plants, and mammals
GO:0000166 nucleotide binding	IEA GO_REF:0000104	KEEP AS NON CORE	Summary: Nucleotide binding is intrinsic to the pyrophosphatase activity and is captured by the more specific substrate-level MF annotations. This generic term adds no functional insight and is redundant. Supporting Evidence: file:9POAL/NCGR_LOCUS3088/NCGR_LOCUS3088-notes.md HAM1/ITPase family is well-characterized across bacteria, yeast, plants, and mammals
GO:0009143 nucleoside triphosphate catabolic process	IEA GO_REF:0000104	KEEP AS NON CORE	Summary: Correct biological process for ITPase activity. The enzyme catalyzes catabolic hydrolysis of nucleoside triphosphates. However, it is a parent of the more specific deoxyribonucleoside triphosphate catabolic process and is somewhat redundant. Keep as non-core. Supporting Evidence: file:9POAL/NCGR_LOCUS3088/NCGR_LOCUS3088-notes.md HAM1/ITPase family is well-characterized across bacteria, yeast, plants, and mammals
GO:0009204 deoxyribonucleoside triphosphate catabolic process	IEA GO_REF:0000104	ACCEPT	Summary: Correct biological process capturing the deoxyribonucleotide catabolism aspect of ITPase function. Well-supported by the enzyme's role in hydrolyzing dITP to prevent deoxyinosine incorporation into DNA [PMID:36464781]. Supporting Evidence: PMID:36464781 ITPA loss-of-function causes inosine di- and triphosphate accumulation in vivo and an elevated inosine and deoxyinosine content in RNA and DNA file:9POAL/NCGR_LOCUS3088/NCGR_LOCUS3088-notes.md HAM1/ITPase family is well-characterized across bacteria, yeast, plants, and mammals
GO:0009117 nucleotide metabolic process	IEA GO_REF:0000104	KEEP AS NON CORE	Summary: Very broad biological process term. Redundant with the more specific catabolic process annotations (GO:0009143, GO:0009204). Provides minimal functional insight. Supporting Evidence: file:9POAL/NCGR_LOCUS3088/NCGR_LOCUS3088-notes.md HAM1/ITPase family is well-characterized across bacteria, yeast, plants, and mammals
GO:0005737 cytoplasm	IEA GO_REF:0000104	ACCEPT	Summary: Cytoplasmic localization is well-supported by HAMAP rule MF_03148 and consistent with the nucleotide pool sanitization function. ITPase orthologs across organisms are cytoplasmic enzymes that act on cytosolic nucleotide pools. Supporting Evidence: PMID:36464781 Inosine triphosphate pyrophosphatase is part of a molecular protection system in plants file:9POAL/NCGR_LOCUS3088/NCGR_LOCUS3088-notes.md HAM1/ITPase family is well-characterized across bacteria, yeast, plants, and mammals