HAMAP rule MF_00179
General rule information
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| Accession | MF_00179 |
| Dates | 1-JUN-2001 (Created)
1-JUN-2023 (Last updated, Version 30) |
| Name | RibA |
| Scope(s) |
Bacteria Archaea |
| Template(s) | P0A7I7 (RIBA_ECOLI); O08315 (RIBA_HELPY); [ Recover all ] |
| Triggered by |
HAMAP; MF_00179 (Get profile general information and statistics) |
Propagated annotation
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Identifier, protein and gene names
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| Identifier | RIBA |
| Protein name | RecName: Full=GTP cyclohydrolase-2; EC=3.5.4.25; AltName: Full=GTP cyclohydrolase II; |
| Gene name | Name=ribA; |
Comments
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| FUNCTION | Catalyzes the conversion of GTP to 2,5-diamino-6- ribosylamino-4(3H)-pyrimidinone 5'-phosphate (DARP), formate and pyrophosphate. |
| CATALYTIC ACTIVITY | Reaction=GTP + 4 H2O = 2,5-diamino-6-hydroxy-4-(5-phosphoribosylamino)- pyrimidine + formate + 3 H(+) + 2 phosphate; Xref=Rhea:RHEA:23704, ChEBI:CHEBI:15377, ChEBI:CHEBI:15378, ChEBI:CHEBI:15740, ChEBI:CHEBI:37565, ChEBI:CHEBI:43474, ChEBI:CHEBI:58614; EC=3.5.4.25; |
| COFACTOR | Name=Zn(2+); Xref=ChEBI:CHEBI:29105; Note=Binds 1 zinc ion per subunit.; |
| PATHWAY | Cofactor biosynthesis; riboflavin biosynthesis; 5-amino-6-(D- ribitylamino)uracil from GTP: step 1/4. |
| case <OC:Enterobacterales> | |
| SUBUNIT | Homodimer. |
| end case | |
| SIMILARITY | Belongs to the GTP cyclohydrolase II family. |
Keywords
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Gene Ontology
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| GO:0003935; Molecular function:GTP cyclohydrolase II activity |
| GO:0008270; Molecular function:zinc ion binding |
| GO:0009231; Biological process:riboflavin biosynthetic process |
Cross-references
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Features
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| From: RIBA_ECOLI (P0A7I7) | ||||||||||||
| Key | From | To | Description | Tag | Condition | FTGroup | ||||||
| BINDING | 49 | 53 | /ligand="GTP" /ligand_id="ChEBI:CHEBI:37565" |
|||||||||
| BINDING | 92 | 94 | /ligand="GTP" /ligand_id="ChEBI:CHEBI:37565" |
E-G-R | ||||||||
| ACT_SITE | 126 | 126 | /note="Proton acceptor" | D | ||||||||
| ACT_SITE | 128 | 128 | /note="Nucleophile" | R | ||||||||
| BINDING | 54 | 54 | /ligand="Zn(2+)" /ligand_id="ChEBI:CHEBI:29105" /ligand_note="catalytic" |
C | ||||||||
| BINDING | 65 | 65 | /ligand="Zn(2+)" /ligand_id="ChEBI:CHEBI:29105" /ligand_note="catalytic" |
C | ||||||||
| BINDING | 67 | 67 | /ligand="Zn(2+)" /ligand_id="ChEBI:CHEBI:29105" /ligand_note="catalytic" |
C | ||||||||
| BINDING | 70 | 70 | /ligand="GTP" /ligand_id="ChEBI:CHEBI:37565" |
Q | ||||||||
| BINDING | 114 | 114 | /ligand="GTP" /ligand_id="ChEBI:CHEBI:37565" |
T | ||||||||
| BINDING | 149 | 149 | /ligand="GTP" /ligand_id="ChEBI:CHEBI:37565" |
[TS] | ||||||||
| BINDING | 154 | 154 | /ligand="GTP" /ligand_id="ChEBI:CHEBI:37565" |
K | ||||||||
Additional information
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| Size range | 192-222 amino acids |
| Related rules |
MF_01283 |
| Fusion | Nter: <ribB-like>; <Unknown> Cter: None |
| Comments | RibA and RibB are fused in some organisms (see MF_01283 for bifunctional RibBA). Some RibA are preceded by a ribB-like domain, which does not seem to code for DHBP synthase activity because it lacks all the residues important for activity. Fused with an unknown N-terminal domain in XYLFA and XYLFT. Possible wrong start in STRCO. |