Organellar GatC subunit of the GatCAB amidotransferase complex that forms correctly charged Gln-tRNA(Gln) by transamidation in chloroplasts and mitochondria.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0005739 mitochondrion | IBA GO_REF:0000033 | ACCEPT | Summary: mitochondrion localization is supported for organellar GatC. Reason: UniProt places GatC in both mitochondrion and chloroplast, and comparative plant evidence shows that plant GatCAB subunits (including GatC) are dual-targeted to both organelles by in vitro import assays in Arabidopsis. Supporting Evidence: file:POPTR/GATC/GATC-uniprot.txt SUBCELLULAR LOCATION: Mitochondrion file:POPTR/GATC/GATC-deep-research-falcon.md GatA, GatB, and GatC** are imported into **both mitochondria and chloroplasts** and processed to mature, protease-protected forms |
| GO:0030956 glutamyl-tRNA(Gln) amidotransferase complex | IBA GO_REF:0000033 | ACCEPT | Summary: GatC is part of the glutamyl-tRNA(Gln) amidotransferase complex. Reason: The protein is a subunit of the heterotrimeric GatCAB amidotransferase complex; in the conserved and plant enzymes GatC is the small accessory/structural subunit that stabilizes the GatA/GatB catalytic core. Supporting Evidence: file:POPTR/GATC/GATC-uniprot.txt Subunit of the heterotrimeric GatCAB amidotransferase (AdT) complex, composed of A, B and C subunits. file:POPTR/GATC/GATC-deep-research-falcon.md GatC as a **structural/linker** element that interacts with GatA and GatB via its termini |
| GO:0032543 mitochondrial translation | IBA GO_REF:0000033 | KEEP AS NON CORE | Summary: Mitochondrial translation is a valid organellar process consequence of Gln-tRNA(Gln) formation but is not the most direct function. Reason: The direct function is tRNA-dependent glutamine formation by transamidation; supplying correctly charged Gln-tRNA(Gln) to organellar ribosomes (mitochondrial translation) is the downstream consequence. Supporting Evidence: file:POPTR/GATC/GATC-uniprot.txt Allows the formation of correctly charged Gln-tRNA(Gln) through the transamidation of misacylated Glu-tRNA(Gln) in chloroplasts and mitochondria. file:POPTR/GATC/GATC-deep-research-falcon.md GatCAB sits in the **organellar translation supply chain**, upstream of ribosomal protein synthesis |
| GO:0070681 glutaminyl-tRNAGln biosynthesis via transamidation | IBA GO_REF:0000033 | ACCEPT | Summary: Glutaminyl-tRNAGln biosynthesis via transamidation is the direct biological process for GatC. Reason: UniProt describes transamidation of misacylated Glu-tRNA(Gln) to correctly charged Gln-tRNA(Gln); in plant organelles this indirect (transamidation) route is the established mechanism for producing Gln-tRNA(Gln). Supporting Evidence: file:POPTR/GATC/GATC-uniprot.txt Allows the formation of correctly charged Gln-tRNA(Gln) through the transamidation of misacylated Glu-tRNA(Gln) in chloroplasts and mitochondria. file:POPTR/GATC/GATC-deep-research-falcon.md It ensures availability of correctly charged **Gln‑tRNA\*Gln\*** in organelles that may not have an organellar GlnRS, by correcting ND‑GluRS misacylation via transamidation |
| GO:0005739 mitochondrion | IEA GO_REF:0000120 | ACCEPT | Summary: mitochondrion localization is supported for organellar GatC. Reason: UniProt places GatC in both mitochondrion and chloroplast, consistent with experimentally demonstrated dual targeting of plant GatCAB subunits to both organelles. Supporting Evidence: file:POPTR/GATC/GATC-uniprot.txt SUBCELLULAR LOCATION: Mitochondrion file:POPTR/GATC/GATC-deep-research-falcon.md GatA, GatB, and GatC** are imported into **both mitochondria and chloroplasts** and processed to mature, protease-protected forms |
| GO:0006450 regulation of translational fidelity | IEA GO_REF:0000002 | KEEP AS NON CORE | Summary: Regulation of translational fidelity is related to correct tRNA charging but is broader than the direct GatC role. Reason: Retain as non-core while using glutaminyl-tRNAGln biosynthesis via transamidation as the direct process; by correcting ND-GluRS misacylation, GatCAB does contribute to faithful organellar translation. Supporting Evidence: file:POPTR/GATC/GATC-uniprot.txt Allows the formation of correctly charged Gln-tRNA(Gln) through the transamidation of misacylated Glu-tRNA(Gln) in chloroplasts and mitochondria. file:POPTR/GATC/GATC-deep-research-falcon.md It ensures availability of correctly charged **Gln‑tRNA\*Gln\*** in organelles that may not have an organellar GlnRS, by correcting ND‑GluRS misacylation via transamidation |
| GO:0009507 chloroplast | IEA GO_REF:0000120 | ACCEPT | Summary: chloroplast localization is supported for organellar GatC. Reason: UniProt places GatC in both mitochondrion and chloroplast; in Arabidopsis, GatA/B/C are imported into both mitochondria and chloroplasts, supporting plastid localization of the Populus ortholog. Supporting Evidence: file:POPTR/GATC/GATC-uniprot.txt Plastid, chloroplast file:POPTR/GATC/GATC-deep-research-falcon.md GatA, GatB, and GatC** are imported into **both mitochondria and chloroplasts** and processed to mature, protease-protected forms |
| GO:0016884 carbon-nitrogen ligase activity, with glutamine as amido-N-donor | IEA GO_REF:0000104 | MODIFY | Summary: Carbon-nitrogen ligase activity with glutamine as amido-N-donor is correct but less specific than the GatCAB reaction term. Reason: This generic parent term should be replaced by the specific GatCAB reaction term, glutaminyl-tRNA synthase (glutamine-hydrolyzing) activity, which is the precise activity of the complex (and is separately annotated for this entry). Proposed replacements: glutaminyl-tRNA synthase (glutamine-hydrolyzing) activity Supporting Evidence: file:POPTR/GATC/GATC-uniprot.txt Reaction=L-glutamyl-tRNA(Gln) + L-glutamine + ATP + H2O = L-glutaminyl- |
| GO:0030956 glutamyl-tRNA(Gln) amidotransferase complex | IEA GO_REF:0000104 | ACCEPT | Summary: GatC is part of the glutamyl-tRNA(Gln) amidotransferase complex. Reason: The protein is a subunit of the heterotrimeric GatCAB amidotransferase complex; GatC is the small accessory subunit required for proper folding of GatA and GatA binding to GatB. Supporting Evidence: file:POPTR/GATC/GATC-uniprot.txt Subunit of the heterotrimeric GatCAB amidotransferase (AdT) complex, composed of A, B and C subunits. file:POPTR/GATC/GATC-deep-research-falcon.md GatC as required for **proper folding of GatA** and for GatA binding to GatB |
| GO:0032543 mitochondrial translation | IEA GO_REF:0000104 | KEEP AS NON CORE | Summary: Mitochondrial translation is a valid organellar process consequence of Gln-tRNA(Gln) formation but is not the most direct function. Reason: The direct function is tRNA-dependent glutamine formation by transamidation; supplying Gln-tRNA(Gln) to organellar ribosomes (mitochondrial translation) is downstream of that activity. Supporting Evidence: file:POPTR/GATC/GATC-uniprot.txt Allows the formation of correctly charged Gln-tRNA(Gln) through the transamidation of misacylated Glu-tRNA(Gln) in chloroplasts and mitochondria. file:POPTR/GATC/GATC-deep-research-falcon.md GatCAB sits in the **organellar translation supply chain**, upstream of ribosomal protein synthesis |
| GO:0050567 glutaminyl-tRNA synthase (glutamine-hydrolyzing) activity | IEA GO_REF:0000120 | ACCEPT | Summary: Glutaminyl-tRNA synthase (glutamine-hydrolyzing) activity is the correct molecular function for GatCAB with GatC as a subunit. Reason: The reaction converts Glu-tRNA(Gln), glutamine, and ATP to Gln-tRNA(Gln); the contributes_to qualifier is appropriate because GatC is the accessory subunit and the catalysis is performed by the assembled GatCAB complex. Supporting Evidence: file:POPTR/GATC/GATC-uniprot.txt Reaction=L-glutamyl-tRNA(Gln) + L-glutamine + ATP + H2O = L-glutaminyl- file:POPTR/GATC/GATC-deep-research-falcon.md **GatC** is a **small accessory subunit** |
| GO:0070681 glutaminyl-tRNAGln biosynthesis via transamidation | IEA GO_REF:0000104 | ACCEPT | Summary: Glutaminyl-tRNAGln biosynthesis via transamidation is the direct biological process for GatC. Reason: UniProt describes transamidation of misacylated Glu-tRNA(Gln) to correctly charged Gln-tRNA(Gln); this indirect two-step pathway (ND-GluRS then GatCAB) is the established route for organellar Gln-tRNA(Gln) in plants. Supporting Evidence: file:POPTR/GATC/GATC-uniprot.txt Allows the formation of correctly charged Gln-tRNA(Gln) through the transamidation of misacylated Glu-tRNA(Gln) in chloroplasts and mitochondria. file:POPTR/GATC/GATC-deep-research-falcon.md Gln-tRNA\*Gln\* is produced by an **indirect two-step pathway** |
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Download this section (compressed HTML)Q: Is Populus GatC dual-targeting to chloroplasts and mitochondria experimentally confirmed by proteomics or fluorescent tagging?
Q: Does GatC abundance limit organellar translational fidelity under stress?
Experiment: Tag endogenous GatC and test co-localization with chloroplast and mitochondrial markers while measuring organellar tRNA charging.
Type: targeted functional assay
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Download this section (compressed HTML)GATC-uniprot.txt and GATC-goa.tsv.Loading supporting content…
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