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HAMAP rule MF_00179

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General rule information [?]

Accession MF_00179
Dates 1-JUN-2001 (Created)
1-JUN-2023 (Last updated, Version 30)
Name RibA
Scope(s) Bacteria
Template(s) P0A7I7 (RIBA_ECOLI); O08315 (RIBA_HELPY); [ Recover all ]
Triggered by HAMAP; MF_00179 (Get profile general information and statistics)

Propagated annotation [?]

Identifier, protein and gene names [?]

Identifier RIBA
Protein name RecName: Full=GTP cyclohydrolase-2;
AltName: Full=GTP cyclohydrolase II;
Gene name Name=ribA;

Comments [?]

FUNCTIONCatalyzes 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=;
COFACTOR Name=Zn(2+); Xref=ChEBI:CHEBI:29105; Note=Binds 1 zinc ion per subunit.;
PATHWAYCofactor biosynthesis; riboflavin biosynthesis; 5-amino-6-(D- ribitylamino)uracil from GTP: step 1/4.
case <OC:Enterobacterales>
end case
SIMILARITYBelongs to the GTP cyclohydrolase II family.

Keywords [?]

Gene Ontology [?]

GO:0003935; Molecular function:GTP cyclohydrolase II activity
GO:0008270; Molecular function:zinc ion binding
GO:0009231; Biological process:riboflavin biosynthetic process

Cross-references [?]

Pfam PF00925; GTP_cyclohydro2; 1;
NCBIfam TIGR00505; RibA; 1;

Features [?]

Key From To Description Tag Condition FTGroup
BINDING 49 53 /ligand="GTP"
BINDING 92 94 /ligand="GTP"
ACT_SITE 126 126 /note="Proton acceptor" D
ACT_SITE 128 128 /note="Nucleophile" R
BINDING 54 54 /ligand="Zn(2+)"
BINDING 65 65 /ligand="Zn(2+)"
BINDING 67 67 /ligand="Zn(2+)"
BINDING 70 70 /ligand="GTP"
BINDING 114 114 /ligand="GTP"
BINDING 149 149 /ligand="GTP"
BINDING 154 154 /ligand="GTP"

Additional information [?]

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.

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