GatA (CG6007; formerly benedict, bene) encodes the A subunit of the mitochondrial glutamyl-tRNA(Gln) amidotransferase (GatCAB). Mitochondria lack a glutaminyl-tRNA synthetase, so mitochondrial tRNA(Gln) is first charged with glutamate and then converted by GatCAB to Gln-tRNA(Gln). GatA is the amidase-family glutaminase subunit: it hydrolyses glutamine and channels the released ammonia to GatB, which activates the misacylated glutamate by phosphorylation and amidates it. The complex is required for synthesis of Gln-tRNA(Gln) used in mitochondrial translation. GatA is mitochondrial, and bene/gatA mutations, recovered in a genetic screen for nuclear genes with mitochondrial function, cause growth defects in mitotic and endoreplicating tissues.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0003824 catalytic activity | IEA GO_REF:0000002 | MODIFY | Summary: Generic catalytic activity from the amidase signature domain. Reason: Uninformative; GatA catalyses glutamine hydrolysis as the glutaminase subunit of GatCAB. The replacement, glutaminase activity, is already annotated (below), so this records the preferred term rather than a new assertion. Proposed replacements: glutaminase activity Supporting Evidence: file:DROME/GatA/GatA-uniprot.txt This subunit probably catalyzes the hydrolysis |
| GO:0004359 glutaminase activity | IEA GO_REF:0000120 | ACCEPT | Summary: Glutaminase activity (the GatA half-reaction). Reason: GatA is the amidase-family subunit that hydrolyses glutamine to supply ammonia to GatB. In GatCAB this activity is coupled to transamidation rather than serving free glutamine catabolism. Supporting Evidence: file:DROME/GatA/GatA-uniprot.txt This subunit probably catalyzes the hydrolysis |
| GO:0005739 mitochondrion | IBA GO_REF:0000033 | ACCEPT | Summary: Mitochondrion. Reason: GatCAB transamidates mitochondrial Glu-tRNA(Gln); all three fly subunits belong to the mitochondrial Gat subfamilies. Supporting Evidence: PMID:26761199 converting Glu to Gln via a heterotrimeric Glu-tRNAGln amidotransferase (Gat) |
| GO:0005739 mitochondrion | IDA PMID:16849596 An efficient genetic screen in Drosophila to identify nuclea... | ACCEPT | Summary: Mitochondrial localization from the Liao et al. mitochondrial-function screen. Reason: The curator read the full text (abstract only cached); the screen characterized genes that each encode mitochondrial proteins, consistent with GatA's mitochondrial role. Supporting Evidence: PMID:16849596 each encodes a mitochondrial protein |
| GO:0005739 mitochondrion | IEA GO_REF:0000120 | ACCEPT | Summary: Mitochondrion. Reason: GatCAB transamidates mitochondrial Glu-tRNA(Gln); all three fly subunits belong to the mitochondrial Gat subfamilies. Supporting Evidence: PMID:26761199 converting Glu to Gln via a heterotrimeric Glu-tRNAGln amidotransferase (Gat) |
| GO:0005759 mitochondrial matrix | NAS PMID:26761199 The aminoacyl-tRNA synthetases of Drosophila melanogaster. | ACCEPT | Summary: Mitochondrial matrix. Reason: The transamidosome acts on mitochondrially encoded tRNA(Gln) in the matrix. Supporting Evidence: PMID:26761199 converting Glu to Gln via a heterotrimeric Glu-tRNAGln amidotransferase (Gat) |
| GO:0006412 translation | IEA GO_REF:0000002 | MODIFY | Summary: Translation (InterPro). Reason: Correct but too general; GatCAB acts only in mitochondrial translation (supplying Gln-tRNA(Gln) in the absence of a mitochondrial GlnRS). MODIFY to mitochondrial translation, which GatA already carries (IBA, IEA, ISS). Proposed replacements: mitochondrial translation |
| GO:0017171 serine hydrolase activity | HDA PMID:33827210 A Superfamily-wide Activity Atlas of Serine Hydrolases in &l... | KEEP AS NON CORE | Summary: Serine hydrolase activity from activity-based protein profiling. Reason: GatA belongs to the amidase-signature family, which uses a catalytic serine, so labelling by a serine-hydrolase probe is expected (curator HDA; GatA not visible in the cached text). The informative activity is glutaminase. |
| GO:0030956 glutamyl-tRNA(Gln) amidotransferase complex | IBA GO_REF:0000033 | ACCEPT | Summary: Subunit of the glutamyl-tRNA(Gln) amidotransferase (GatCAB) complex. Reason: Flies encode single GatA, GatB and GatC orthologs, which together form the heterotrimeric mitochondrial amidotransferase. Supporting Evidence: PMID:26761199 CG5463 and CG33649 genes – we propose to name the latter two GatB and GatC, respectively file:DROME/GatA/GatA-deep-research-falcon.md found GatA to be the only obvious fly ortholog of this amidotransferase subunit |
| GO:0030956 glutamyl-tRNA(Gln) amidotransferase complex | IEA GO_REF:0000120 | ACCEPT | Summary: Subunit of the glutamyl-tRNA(Gln) amidotransferase (GatCAB) complex. Reason: Flies encode single GatA, GatB and GatC orthologs, which together form the heterotrimeric mitochondrial amidotransferase. Supporting Evidence: PMID:26761199 CG5463 and CG33649 genes – we propose to name the latter two GatB and GatC, respectively file:DROME/GatA/GatA-deep-research-falcon.md found GatA to be the only obvious fly ortholog of this amidotransferase subunit |
| GO:0030956 glutamyl-tRNA(Gln) amidotransferase complex | ISS GO_REF:0000024 | ACCEPT | Summary: Subunit of the glutamyl-tRNA(Gln) amidotransferase (GatCAB) complex. Reason: Flies encode single GatA, GatB and GatC orthologs, which together form the heterotrimeric mitochondrial amidotransferase. Supporting Evidence: PMID:26761199 CG5463 and CG33649 genes – we propose to name the latter two GatB and GatC, respectively file:DROME/GatA/GatA-deep-research-falcon.md found GatA to be the only obvious fly ortholog of this amidotransferase subunit |
| GO:0030956 glutamyl-tRNA(Gln) amidotransferase complex | NAS PMID:26761199 The aminoacyl-tRNA synthetases of Drosophila melanogaster. | ACCEPT | Summary: Subunit of the glutamyl-tRNA(Gln) amidotransferase (GatCAB) complex. Reason: Flies encode single GatA, GatB and GatC orthologs, which together form the heterotrimeric mitochondrial amidotransferase. Supporting Evidence: PMID:26761199 CG5463 and CG33649 genes – we propose to name the latter two GatB and GatC, respectively file:DROME/GatA/GatA-deep-research-falcon.md found GatA to be the only obvious fly ortholog of this amidotransferase subunit |
| GO:0032543 mitochondrial translation | IBA GO_REF:0000033 | KEEP AS NON CORE | Summary: Mitochondrial translation. Reason: GatCAB supplies Gln-tRNA(Gln) for mitochondrial protein synthesis (there is no mitochondrial GlnRS), so the involvement is real, but the specific step is captured better by conversion of glutamyl-tRNA to glutaminyl-tRNA. Supporting Evidence: PMID:26761199 converting Glu to Gln via a heterotrimeric Glu-tRNAGln amidotransferase (Gat) |
| GO:0032543 mitochondrial translation | IEA GO_REF:0000104 | KEEP AS NON CORE | Summary: Mitochondrial translation. Reason: GatCAB supplies Gln-tRNA(Gln) for mitochondrial protein synthesis (there is no mitochondrial GlnRS), so the involvement is real, but the specific step is captured better by conversion of glutamyl-tRNA to glutaminyl-tRNA. Supporting Evidence: PMID:26761199 converting Glu to Gln via a heterotrimeric Glu-tRNAGln amidotransferase (Gat) |
| GO:0032543 mitochondrial translation | ISS GO_REF:0000024 | KEEP AS NON CORE | Summary: Mitochondrial translation. Reason: GatCAB supplies Gln-tRNA(Gln) for mitochondrial protein synthesis (there is no mitochondrial GlnRS), so the involvement is real, but the specific step is captured better by conversion of glutamyl-tRNA to glutaminyl-tRNA. Supporting Evidence: PMID:26761199 converting Glu to Gln via a heterotrimeric Glu-tRNAGln amidotransferase (Gat) |
| GO:0050567 glutaminyl-tRNA synthase (glutamine-hydrolyzing) activity | IBA GO_REF:0000033 | ACCEPT | Summary: Contributes to glutaminyl-tRNA synthase (glutamine-hydrolyzing) activity. Reason: The overall transamidation needs all three subunits; GatA supplies ammonia from glutamine. Supporting Evidence: file:DROME/GatA/GatA-uniprot.txt Catalytic subunit of the mitochondrial Glu-tRNA(Gln) |
| GO:0050567 glutaminyl-tRNA synthase (glutamine-hydrolyzing) activity | IEA GO_REF:0000002 | MARK AS OVER ANNOTATED | Summary: Glutaminyl-tRNA synthase (glutamine-hydrolyzing) activity with enables qualifier (InterPro). Reason: GatA catalyses glutamine hydrolysis (EC 3.5.1.2, glutaminase activity, annotated separately), not the EC 6.3.5.7 ligase reaction, which GatB performs. GatA only contributes to the holoenzyme activity, as the contributes_to rows state, so an enables row overstates its own activity. This matches the treatment of the non-catalytic TGT subunit CG3434. Supporting Evidence: file:DROME/GatA/GatA-uniprot.txt Catalytic subunit of the mitochondrial Glu-tRNA(Gln) |
| GO:0050567 glutaminyl-tRNA synthase (glutamine-hydrolyzing) activity | ISS PMID:26761199 The aminoacyl-tRNA synthetases of Drosophila melanogaster. | ACCEPT | Summary: Contributes to glutaminyl-tRNA synthase (glutamine-hydrolyzing) activity. Reason: The overall transamidation needs all three subunits; GatA supplies ammonia from glutamine. Supporting Evidence: file:DROME/GatA/GatA-uniprot.txt Catalytic subunit of the mitochondrial Glu-tRNA(Gln) |
| GO:0070681 obsolete glutaminyl-tRNAGln biosynthesis via transamidation | IBA GO_REF:0000033 | MODIFY | Summary: Obsolete glutaminyl-tRNAGln biosynthesis via transamidation. Reason: The term was obsoleted with no automatic replacement. The subunit takes part in transamidation of misacylated Glu-tRNA(Gln) to Gln-tRNA(Gln), which is described by GO:0043685 conversion of glutamyl-tRNA to glutaminyl-tRNA. Propagation Review Root cause: SOURCE STALE OR MISSING Proposed replacements: conversion of glutamyl-tRNA to glutaminyl-tRNA Supporting Evidence: PMID:26761199 converting Glu to Gln via a heterotrimeric Glu-tRNAGln amidotransferase (Gat) |
| GO:0070681 obsolete glutaminyl-tRNAGln biosynthesis via transamidation | IEA GO_REF:0000104 | MODIFY | Summary: Obsolete glutaminyl-tRNAGln biosynthesis via transamidation. Reason: The term was obsoleted with no automatic replacement. The subunit takes part in transamidation of misacylated Glu-tRNA(Gln) to Gln-tRNA(Gln), which is described by GO:0043685 conversion of glutamyl-tRNA to glutaminyl-tRNA. Propagation Review Root cause: SOURCE STALE OR MISSING Proposed replacements: conversion of glutamyl-tRNA to glutaminyl-tRNA Supporting Evidence: PMID:26761199 converting Glu to Gln via a heterotrimeric Glu-tRNAGln amidotransferase (Gat) |
| GO:0070681 obsolete glutaminyl-tRNAGln biosynthesis via transamidation | ISS PMID:26761199 The aminoacyl-tRNA synthetases of Drosophila melanogaster. | MODIFY | Summary: Obsolete glutaminyl-tRNAGln biosynthesis via transamidation. Reason: The term was obsoleted with no automatic replacement. The subunit takes part in transamidation of misacylated Glu-tRNA(Gln) to Gln-tRNA(Gln), which is described by GO:0043685 conversion of glutamyl-tRNA to glutaminyl-tRNA. Propagation Review Root cause: SOURCE STALE OR MISSING Proposed replacements: conversion of glutamyl-tRNA to glutaminyl-tRNA Supporting Evidence: PMID:26761199 converting Glu to Gln via a heterotrimeric Glu-tRNAGln amidotransferase (Gat) |
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Download this section (compressed HTML)Q: Is fly GatCAB the only route to mitochondrial Gln-tRNA(Gln), and which mitochondrial phenotype from the Liao et al. screen maps to GatA?
Experiment: Acid-urea northern blots of mt-tRNA(Gln) aminoacylation and mitochondrial translation labelling in GatA mutant tissue.
Hypothesis: GatA loss leaves mitochondrial tRNA(Gln) charged with glutamate and blocks mitochondrial translation.
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