rib2 (SPCC4G3.16; UniProt P87241) encodes a bifunctional protein. Its C-terminal CMP/dCMP-type deaminase domain deaminates 2,5-diamino-6-ribitylamino-pyrimidinone 5'-phosphate in riboflavin biosynthesis (EC 3.5.4.26), the step after the RIB7-type reduction. Its N-terminal domain is a SAM-dependent protein-lysine N-methyltransferase by similarity, with no known substrate. The domain arrangement differs from S. cerevisiae Rib2, which pairs the deaminase with a pseudouridine synthase. The protein is cytosolic in a genome-wide screen.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0005634 nucleus | HDA PMID:16823372 ORFeome cloning and global analysis of protein localization ... | KEEP AS NON CORE | Summary: ORFeome YFP screen recorded nuclear signal for rib2. Soluble metabolic enzymes often show diffuse nucleocytoplasmic signal in this screen; no nuclear role is known. Reason: Experimental HDA kept, but not part of the core function. Supporting Evidence: PMID:16823372 we determined the localization of 4,431 proteins |
| GO:0005634 nucleus | IEA GO_REF:0000044 | KEEP AS NON CORE | Summary: UniProt location mapping of the nuclear screen signal; no nuclear role known. Reason: Not part of the core function. Supporting Evidence: PMID:16823372 we determined the localization of 4,431 proteins |
| GO:0005737 cytoplasm | EXP PMID:16823372 ORFeome cloning and global analysis of protein localization ... | ACCEPT | Summary: Cytoplasmic signal in the ORFeome screen. Supporting Evidence: PMID:16823372 we determined the localization of 4,431 proteins |
| GO:0005739 mitochondrion | ISO GO_REF:0000024 | KEEP AS NON CORE | Summary: Transfer of mitochondrial location from S. cerevisiae (proteomics); not shown in S. pombe. Reason: Not established. Supporting Evidence: PMID:16823372 we determined the localization of 4,431 proteins |
| GO:0005829 cytosol | HDA PMID:16823372 ORFeome cloning and global analysis of protein localization ... | ACCEPT | Summary: ORFeome YFP screen placed rib2 in the cytosol, consistent with a soluble metabolic enzyme. Supporting Evidence: PMID:16823372 we determined the localization of 4,431 proteins |
| GO:0005829 cytosol | IEA GO_REF:0000044 | ACCEPT | Summary: UniProt subcellular-location mapping (cytosol), derived from the localisation screen. Supporting Evidence: PMID:16823372 we determined the localization of 4,431 proteins |
| GO:0008276 protein methyltransferase activity | IBA GO_REF:0000033 | KEEP AS NON CORE | Summary: PAINT inference of protein methyltransferase activity for the N-terminal domain (lysine methyltransferase by similarity). Substrate unknown in S. pombe. Supporting Evidence: file:SCHPO/rib2/rib2-uniprot.txt FUNCTION: S-adenosyl-L-methionine-dependent protein-lysine N- |
| GO:0008835 diaminohydroxyphosphoribosylaminopyrimidine deaminase activity | IEA GO_REF:0000120 | ACCEPT | Summary: EC/RHEA mapping of the C-terminal CMP/dCMP-type deaminase: the riboflavin-pathway deaminase step. Supporting Evidence: file:SCHPO/rib2/rib2-uniprot.txt FUNCTION: Involved in riboflavin biosynthesis. Converts 2,5-diamino-6- file:SCHPO/rib2/rib2-uniprot.txt /note="CMP/dCMP-type deaminase" |
| GO:0008835 diaminohydroxyphosphoribosylaminopyrimidine deaminase activity | ISS GO_REF:0000024 | ACCEPT | Summary: Curator transfer from the Aquifex RibD deaminase (O66534). Supporting Evidence: file:SCHPO/rib2/rib2-uniprot.txt FUNCTION: Involved in riboflavin biosynthesis. Converts 2,5-diamino-6- |
| GO:0009231 riboflavin biosynthetic process | IEA GO_REF:0000041 | ACCEPT | Summary: UniPathway mapping; consistent. Supporting Evidence: file:SCHPO/rib2/rib2-uniprot.txt FUNCTION: Involved in riboflavin biosynthesis. Converts 2,5-diamino-6- |
| GO:0009231 riboflavin biosynthetic process | ISO GO_REF:0000024 | ACCEPT | Summary: Transfer from S. cerevisiae RIB2. Supporting Evidence: file:SCHPO/rib2/rib2-uniprot.txt FUNCTION: Involved in riboflavin biosynthesis. Converts 2,5-diamino-6- |
| GO:0016279 protein-lysine N-methyltransferase activity | IEA GO_REF:0000116 | KEEP AS NON CORE | Summary: RHEA mapping of protein-lysine N-methyltransferase activity by similarity; as above. Supporting Evidence: file:SCHPO/rib2/rib2-uniprot.txt FUNCTION: S-adenosyl-L-methionine-dependent protein-lysine N- |
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Download this section (compressed HTML)Q: What protein does the N-terminal lysine methyltransferase domain of S. pombe rib2 methylate, and is that activity linked to riboflavin synthesis?
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