Mrm2 is a mitochondrial RlmE-family rRNA 2-prime-O-methyltransferase and large-ribosomal-subunit assembly factor. Its N-terminal targeting sequence directs it toward the mitochondrial compartment, where homologous MRM2 proteins modify rRNA and support late mitoribosome maturation. Fly knockdown severely impairs development; biochemical work on human MRM2 separates its assembly requirement from its methyltransferase activity.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0000027 ribosomal large subunit assembly | IBA GO_REF:0000033 | MODIFY | Summary: The assembly role is specific to the mitochondrial large ribosomal subunit. Reason: The primary study establishes MRM2 as a late-stage mitochondrial ribosome assembly factor and demonstrates a developmental requirement for the fly ortholog. The mitochondrial term specifies the inherited broad assembly annotation. Proposed replacements: mitochondrial large ribosomal subunit assembly Supporting Evidence: PMID:35177605 The catalytic activity of MRM2 is dispensable for mtLSU biogenesis PMID:35177605 we knocked-down the MRM2 D. melanogaster orthologue CG11447 |
| GO:0005739 mitochondrion | IBA GO_REF:0000033 | ACCEPT | Summary: Mrm2 is a mitochondrial rRNA-modification and assembly protein. Reason: The N-terminal mitochondrial targeting feature and conserved MRM2 substrate/function place the protein inside mitochondria. Fly knockdown in the cross-species mechanistic study supports physiological relevance. Supporting Evidence: file:DROME/Mrm2/Mrm2-uniprot.txt FT TRANSIT 1..35 PMID:35177605 we knocked-down the MRM2 D. melanogaster orthologue CG11447 |
| GO:0005739 mitochondrion | IEA GO_REF:0000120 | ACCEPT | Summary: Mrm2 is a mitochondrial rRNA-modification and assembly protein. Reason: The N-terminal mitochondrial targeting feature and conserved MRM2 substrate/function place the protein inside mitochondria. Fly knockdown in the cross-species mechanistic study supports physiological relevance. Supporting Evidence: file:DROME/Mrm2/Mrm2-uniprot.txt FT TRANSIT 1..35 PMID:35177605 we knocked-down the MRM2 D. melanogaster orthologue CG11447 |
| GO:0005739 mitochondrion | ISS GO_REF:0000024 | ACCEPT | Summary: Mrm2 is a mitochondrial rRNA-modification and assembly protein. Reason: The N-terminal mitochondrial targeting feature and conserved MRM2 substrate/function place the protein inside mitochondria. Fly knockdown in the cross-species mechanistic study supports physiological relevance. Supporting Evidence: file:DROME/Mrm2/Mrm2-uniprot.txt FT TRANSIT 1..35 PMID:35177605 we knocked-down the MRM2 D. melanogaster orthologue CG11447 |
| GO:0005759 mitochondrial matrix | IC PMID:35177605 A late-stage assembly checkpoint of the human mitochondrial ... | ACCEPT | Summary: The mitochondrial matrix is the appropriate compartment for mitoribosome assembly. Reason: MRM2 associates with the large mitochondrial ribosomal subunit; the matrix assignment is a justified compartment inference rather than direct fly imaging. Supporting Evidence: PMID:35177605 The catalytic activity of MRM2 is dispensable for mtLSU biogenesis file:DROME/Mrm2/Mrm2-uniprot.txt FT TRANSIT 1..35 |
| GO:0006364 rRNA processing | ISS PMID:35177605 A late-stage assembly checkpoint of the human mitochondrial ... | ACCEPT | Summary: Mrm2 participates in maturation of mitochondrial rRNA-containing particles. Reason: The large-subunit assembly and rRNA modification mechanisms support the broad rRNA-processing term. This need not imply endonucleolytic RNA cleavage by Mrm2. Supporting Evidence: PMID:35177605 The catalytic activity of MRM2 is dispensable for mtLSU biogenesis PMID:35177605 MRM2 is also a S -adenosyl methionine (SAM)-dependent 2′- O -ribose methyltransferase |
| GO:0008168 methyltransferase activity | IEA GO_REF:0000002 | MODIFY | Summary: rRNA uridine ribose methylation specifies the broad methyltransferase annotation. Reason: MRM2 is an RlmE-family rRNA 2-prime-O methyltransferase; the substrate-specific term is already supported by the ortholog biochemistry and conserved target architecture. Proposed replacements: rRNA (uridine-2'-O-ribose)-methyltransferase activity Supporting Evidence: PMID:35177605 MRM2 is also a S -adenosyl methionine (SAM)-dependent 2′- O -ribose methyltransferase |
| GO:0008650 rRNA (uridine-2'-O-ribose)-methyltransferase activity | IBA GO_REF:0000033 | ACCEPT | Summary: Mrm2 has the conserved rRNA uridine 2-prime-O methyltransferase function. Reason: Human MRM2 mechanistic work and the target RlmE/MRM2 domain placement support transfer of this reaction. The fly experiment is an organismal knockdown, not a direct fly methylation assay; methylation and assembly roles can be separable. Supporting Evidence: PMID:35177605 MRM2 is also a S -adenosyl methionine (SAM)-dependent 2′- O -ribose methyltransferase PMID:35177605 we knocked-down the MRM2 D. melanogaster orthologue CG11447 |
| GO:0008650 rRNA (uridine-2'-O-ribose)-methyltransferase activity | IEA GO_REF:0000116 | ACCEPT | Summary: Mrm2 has the conserved rRNA uridine 2-prime-O methyltransferase function. Reason: Human MRM2 mechanistic work and the target RlmE/MRM2 domain placement support transfer of this reaction. The fly experiment is an organismal knockdown, not a direct fly methylation assay; methylation and assembly roles can be separable. Supporting Evidence: PMID:35177605 MRM2 is also a S -adenosyl methionine (SAM)-dependent 2′- O -ribose methyltransferase PMID:35177605 we knocked-down the MRM2 D. melanogaster orthologue CG11447 |
| GO:0008650 rRNA (uridine-2'-O-ribose)-methyltransferase activity | ISS GO_REF:0000024 | ACCEPT | Summary: Mrm2 has the conserved rRNA uridine 2-prime-O methyltransferase function. Reason: Human MRM2 mechanistic work and the target RlmE/MRM2 domain placement support transfer of this reaction. The fly experiment is an organismal knockdown, not a direct fly methylation assay; methylation and assembly roles can be separable. Supporting Evidence: PMID:35177605 MRM2 is also a S -adenosyl methionine (SAM)-dependent 2′- O -ribose methyltransferase PMID:35177605 we knocked-down the MRM2 D. melanogaster orthologue CG11447 |
| GO:0008650 rRNA (uridine-2'-O-ribose)-methyltransferase activity | ISS PMID:35177605 A late-stage assembly checkpoint of the human mitochondrial ... | ACCEPT | Summary: Mrm2 has the conserved rRNA uridine 2-prime-O methyltransferase function. Reason: Human MRM2 mechanistic work and the target RlmE/MRM2 domain placement support transfer of this reaction. The fly experiment is an organismal knockdown, not a direct fly methylation assay; methylation and assembly roles can be separable. Supporting Evidence: PMID:35177605 MRM2 is also a S -adenosyl methionine (SAM)-dependent 2′- O -ribose methyltransferase PMID:35177605 we knocked-down the MRM2 D. melanogaster orthologue CG11447 |
| GO:0031167 rRNA methylation | IBA GO_REF:0000033 | ACCEPT | Summary: Mitochondrial rRNA methylation is the direct reaction-level process. Reason: The inherited rRNA methylation function is consistent with MRM2 enzymology and its mitochondrial targeting. The exact human rRNA nucleotide number is not assumed to be identical in fly. Supporting Evidence: PMID:35177605 MRM2 is also a S -adenosyl methionine (SAM)-dependent 2′- O -ribose methyltransferase file:DROME/Mrm2/Mrm2-uniprot.txt FT TRANSIT 1..35 |
| GO:1902775 mitochondrial large ribosomal subunit assembly | IMP PMID:35177605 A late-stage assembly checkpoint of the human mitochondrial ... | ACCEPT | Summary: Mitochondrial large-subunit assembly is a core noncatalytic role. Reason: The primary paper defines the late assembly checkpoint and includes the Drosophila ortholog. The assembly role remains valid even when methyltransferase catalysis is dispensable in human complementation experiments. Supporting Evidence: PMID:35177605 The catalytic activity of MRM2 is dispensable for mtLSU biogenesis PMID:35177605 we knocked-down the MRM2 D. melanogaster orthologue CG11447 |
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