GlnS is a cytosolic class-I glutaminyl-tRNA synthetase. It activates glutamine with ATP and transfers it directly to tRNA(Gln), producing the charged tRNA used to decode glutamine codons. This direct route is chemically distinct from GatABC-dependent amidation of Glu-tRNA(Gln).
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0000166 nucleotide binding | IEA GO_REF:0000002 | MODIFY | Summary: glnS binds ATP as part of its aminoacylation machinery. Reason: Nucleotide binding is true but broad. The curated glutamine reaction and relevant subunit architecture support the more specific ATP-binding claim; this is integral substrate recognition, not a peripheral role. Proposed replacements: ATP binding Supporting Evidence: file:PSEPK/glnS/glnS-uniprot.txt Reaction=tRNA(Gln) + L-glutamine + ATP = L-glutaminyl-tRNA(Gln) + AMP + diphosphate; Xref=Rhea:RHEA:20121, Rhea:RHEA-COMP:9662, Rhea:RHEA- COMP:9681, ChEBI:CHEBI:30616, ChEBI:CHEBI:33019, ChEBI:CHEBI:58359, ChEBI:CHEBI:78442, ChEBI:CHEBI:78521, ChEBI:CHEBI:456215; EC=6.1.1.18; Evidence={ECO:0000255|HAMAP-Rule:MF_00126}; |
| GO:0004812 aminoacyl-tRNA ligase activity | IEA GO_REF:0000120 | MODIFY | Summary: glnS has a defined role in the substrate-specific catalytic reaction. Reason: Refine the broad activity to the supported glutamine-tRNA ligase activity. The exact KT2440 curated family/rule assignment supports function by homology, not a purified-target experiment. Proposed replacements: glutamine-tRNA ligase activity Supporting Evidence: file:PSEPK/glnS/glnS-uniprot.txt Reaction=tRNA(Gln) + L-glutamine + ATP = L-glutaminyl-tRNA(Gln) + AMP + diphosphate; Xref=Rhea:RHEA:20121, Rhea:RHEA-COMP:9662, Rhea:RHEA- COMP:9681, ChEBI:CHEBI:30616, ChEBI:CHEBI:33019, ChEBI:CHEBI:58359, ChEBI:CHEBI:78442, ChEBI:CHEBI:78521, ChEBI:CHEBI:456215; EC=6.1.1.18; Evidence={ECO:0000255|HAMAP-Rule:MF_00126}; file:PSEPK/glnS/glnS-uniprot.txt Belongs to the class-I aminoacyl-tRNA synthetase family. {ECO:0000255|HAMAP-Rule:MF_00126}. |
| GO:0004819 glutamine-tRNA ligase activity | IEA GO_REF:0000120 | ACCEPT | Summary: glnS supports its substrate-specific tRNA-ligase activity. Reason: The exact native protein has the corresponding curated HAMAP family/domain and reaction assignment. This supports conserved catalytic capability by homology, not direct KT2440 purification. Supporting Evidence: file:PSEPK/glnS/glnS-uniprot.txt Reaction=tRNA(Gln) + L-glutamine + ATP = L-glutaminyl-tRNA(Gln) + AMP + diphosphate; Xref=Rhea:RHEA:20121, Rhea:RHEA-COMP:9662, Rhea:RHEA- COMP:9681, ChEBI:CHEBI:30616, ChEBI:CHEBI:33019, ChEBI:CHEBI:58359, ChEBI:CHEBI:78442, ChEBI:CHEBI:78521, ChEBI:CHEBI:456215; EC=6.1.1.18; Evidence={ECO:0000255|HAMAP-Rule:MF_00126}; file:PSEPK/glnS/glnS-uniprot.txt Belongs to the class-I aminoacyl-tRNA synthetase family. {ECO:0000255|HAMAP-Rule:MF_00126}. |
| GO:0005524 ATP binding | IEA GO_REF:0000120 | ACCEPT | Summary: glnS contributes integral ATP recognition to its enzymatic reaction. Reason: ATP binding is an integral biochemical property, not a non-core activity merely because it is binding. The curated reaction/architecture supports it by homology for KT2440. Supporting Evidence: file:PSEPK/glnS/glnS-uniprot.txt Reaction=tRNA(Gln) + L-glutamine + ATP = L-glutaminyl-tRNA(Gln) + AMP + diphosphate; Xref=Rhea:RHEA:20121, Rhea:RHEA-COMP:9662, Rhea:RHEA- COMP:9681, ChEBI:CHEBI:30616, ChEBI:CHEBI:33019, ChEBI:CHEBI:58359, ChEBI:CHEBI:78442, ChEBI:CHEBI:78521, ChEBI:CHEBI:456215; EC=6.1.1.18; Evidence={ECO:0000255|HAMAP-Rule:MF_00126}; |
| GO:0005737 cytoplasm | IEA GO_REF:0000120 | MODIFY | Summary: glnS acts in the soluble intracellular tRNA-processing system. Reason: The soluble intracellular synthetase acts on cellular tRNAs; refine cytoplasm to the already retained cytosol term. This is a conserved biochemical/localization inference, not native microscopy. Proposed replacements: cytosol Supporting Evidence: file:PSEPK/glnS/glnS-uniprot.txt Cytoplasm {ECO:0000255|HAMAP-Rule:MF_00126}. |
| GO:0005829 cytosol | IEA GO_REF:0000118 | ACCEPT | Summary: glnS acts in the bacterial cytosol. Reason: The conserved soluble enzyme architecture and curated intracellular localization support this core location. Direct KT2440 imaging is not claimed; lack of such an experiment does not make the supported core location peripheral. Supporting Evidence: file:PSEPK/glnS/glnS-uniprot.txt Cytoplasm {ECO:0000255|HAMAP-Rule:MF_00126}. |
| GO:0006412 translation | IEA GO_REF:0000002 | MODIFY | Summary: glnS performs a defined chemical step supplying translation substrates. Reason: glnS directly participates in ATP-dependent glutamine attachment to tRNA for protein translation. Use the precise translational charging process rather than the broader parent; do not retain obsolete substrate-specific BP terms. Proposed replacements: tRNA aminoacylation for protein translation Supporting Evidence: file:PSEPK/glnS/glnS-uniprot.txt Reaction=tRNA(Gln) + L-glutamine + ATP = L-glutaminyl-tRNA(Gln) + AMP + diphosphate; Xref=Rhea:RHEA:20121, Rhea:RHEA-COMP:9662, Rhea:RHEA- COMP:9681, ChEBI:CHEBI:30616, ChEBI:CHEBI:33019, ChEBI:CHEBI:58359, ChEBI:CHEBI:78442, ChEBI:CHEBI:78521, ChEBI:CHEBI:456215; EC=6.1.1.18; Evidence={ECO:0000255|HAMAP-Rule:MF_00126}; |
| GO:0006418 tRNA aminoacylation for protein translation | IEA GO_REF:0000120 | ACCEPT | Summary: glnS directly supplies aminoacyl-tRNA for protein translation. Reason: The curated glutamine–tRNA reaction forms the amino-acid–tRNA ester bond used in translation. This is the current process term, not overannotation merely because a former substrate-specific BP was more detailed. Supporting Evidence: file:PSEPK/glnS/glnS-uniprot.txt Reaction=tRNA(Gln) + L-glutamine + ATP = L-glutaminyl-tRNA(Gln) + AMP + diphosphate; Xref=Rhea:RHEA:20121, Rhea:RHEA-COMP:9662, Rhea:RHEA- COMP:9681, ChEBI:CHEBI:30616, ChEBI:CHEBI:33019, ChEBI:CHEBI:58359, ChEBI:CHEBI:78442, ChEBI:CHEBI:78521, ChEBI:CHEBI:456215; EC=6.1.1.18; Evidence={ECO:0000255|HAMAP-Rule:MF_00126}; |
| GO:0006424 glutamyl-tRNA aminoacylation | IEA GO_REF:0000104 | MODIFY | Summary: glnS contributes to translational tRNA aminoacylation; the old substrate-specific BP is obsolete. Reason: Current QuickGO marks this substrate-specific process obsolete because it restates a molecular function. Preserve the original GOA term while replacing it with GO:0006418; retain substrate specificity in the supported ligase molecular function. The historical glutamyl-tRNA aminoacylation assignment also misstates this protein's substrate: the native curated classification supports glutamine charging. The replacement does not endorse the former wrong-substrate label. Proposed replacements: tRNA aminoacylation for protein translation Supporting Evidence: file:PSEPK/glnS/glnS-uniprot.txt Reaction=tRNA(Gln) + L-glutamine + ATP = L-glutaminyl-tRNA(Gln) + AMP + diphosphate; Xref=Rhea:RHEA:20121, Rhea:RHEA-COMP:9662, Rhea:RHEA- COMP:9681, ChEBI:CHEBI:30616, ChEBI:CHEBI:33019, ChEBI:CHEBI:58359, ChEBI:CHEBI:78442, ChEBI:CHEBI:78521, ChEBI:CHEBI:456215; EC=6.1.1.18; Evidence={ECO:0000255|HAMAP-Rule:MF_00126}; |
| GO:0006425 glutaminyl-tRNA aminoacylation | IEA GO_REF:0000120 | MODIFY | Summary: glnS contributes to translational tRNA aminoacylation; the old substrate-specific BP is obsolete. Reason: Current QuickGO marks this substrate-specific process obsolete because it restates a molecular function. Preserve the original GOA term while replacing it with GO:0006418; retain substrate specificity in the supported ligase molecular function. Proposed replacements: tRNA aminoacylation for protein translation Supporting Evidence: file:PSEPK/glnS/glnS-uniprot.txt Reaction=tRNA(Gln) + L-glutamine + ATP = L-glutaminyl-tRNA(Gln) + AMP + diphosphate; Xref=Rhea:RHEA:20121, Rhea:RHEA-COMP:9662, Rhea:RHEA- COMP:9681, ChEBI:CHEBI:30616, ChEBI:CHEBI:33019, ChEBI:CHEBI:58359, ChEBI:CHEBI:78442, ChEBI:CHEBI:78521, ChEBI:CHEBI:456215; EC=6.1.1.18; Evidence={ECO:0000255|HAMAP-Rule:MF_00126}; |
| GO:0043039 tRNA aminoacylation | IEA GO_REF:0000002 | MODIFY | Summary: glnS performs a defined chemical step supplying translation substrates. Reason: glnS directly participates in ATP-dependent glutamine attachment to tRNA for protein translation. Use the precise translational charging process rather than the broader parent; do not retain obsolete substrate-specific BP terms. Proposed replacements: tRNA aminoacylation for protein translation Supporting Evidence: file:PSEPK/glnS/glnS-uniprot.txt Reaction=tRNA(Gln) + L-glutamine + ATP = L-glutaminyl-tRNA(Gln) + AMP + diphosphate; Xref=Rhea:RHEA:20121, Rhea:RHEA-COMP:9662, Rhea:RHEA- COMP:9681, ChEBI:CHEBI:30616, ChEBI:CHEBI:33019, ChEBI:CHEBI:58359, ChEBI:CHEBI:78442, ChEBI:CHEBI:78521, ChEBI:CHEBI:456215; EC=6.1.1.18; Evidence={ECO:0000255|HAMAP-Rule:MF_00126}; |
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Experiment: Measure native GlnS aminoacylation kinetics with glutamine and homologous tRNA(Gln), and compare charged-tRNA pools across controlled glutamine availability.
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