MnmA is an ATP-dependent tRNA-uridine 2-sulfurtransferase that catalyzes formation of 2-thiouridine at wobble position U34 in substrate tRNAs. It is the terminal enzyme of the IscS-TusA-TusBCD-TusE sulfur relay.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0002143 tRNA wobble position uridine thiolation | IEA GO_REF:0000118 | ACCEPT | Summary: This is the specific biological process catalyzed by MnmA. Reason: The reviewed UniProt record and MnmA family assignment explicitly support U34 thiolation. |
| GO:0005737 cytoplasm | IEA GO_REF:0000120 | ACCEPT | Summary: MnmA acts on cytoplasmic bacterial tRNAs. Reason: The reviewed UniProt record assigns cytoplasmic localization. |
| GO:0006400 tRNA modification | IEA GO_REF:0000104 | KEEP AS NON CORE | Summary: Correct but less specific than wobble-uridine thiolation. Reason: GO:0002143 captures the direct modification pathway. |
| GO:0008033 tRNA processing | IEA GO_REF:0000002 | KEEP AS NON CORE | Summary: Correct at a broad level but not informative for the direct reaction. Reason: The specific tRNA thiolation term is preferred. |
| GO:0016740 transferase activity | IEA GO_REF:0000120 | KEEP AS NON CORE | Summary: Correct but extremely broad. Reason: GO:0103016 provides the precise catalytic activity. |
| GO:0016783 sulfurtransferase activity | IEA GO_REF:0000002 | KEEP AS NON CORE | Summary: Correct but less specific than the tRNA-uridine sulfurtransferase term. Reason: GO:0103016 identifies both substrate and chemistry. |
| GO:0103016 tRNA-uridine 2-sulfurtransferase activity | IEA GO_REF:0000120 | ACCEPT | Summary: This is the direct catalytic activity of MnmA. Reason: UniProt assigns EC 2.8.1.13 and explicitly describes U34 2-thiolation. |
| GO:0005524 ATP binding | TAS file:PSEPK/mnmA/mnmA-uniprot.txt | NEW | Summary: MnmA binds ATP to activate U34 before sulfur incorporation. Reason: ATP binding is absent from the fetched GOA table but is directly supported by the UniProt GO cross-reference and three ATP-binding features, consistent with the adenylated tRNA intermediate. Supporting Evidence: file:PSEPK/mnmA/mnmA-uniprot.txt DR GO; GO:0005524; F:ATP binding; IEA:UniProtKB-KW. PMID:16871210 The adenylated RNA intermediate is trapped. |
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Download this section (compressed HTML)Q: Which KT2440 tRNA species and growth conditions show the strongest dependence on MnmA?
Experiment: Quantify U34 thiolation across individual tRNAs in wild type and mnmA-null cells.
Type: tRNA modification profiling
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