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HAMAP rule MF_01283

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General rule information [?]

Accession MF_01283
Dates 16-NOV-2007 (Created)
1-JUN-2023 (Last updated, Version 20)
Name RibBA
Scope(s) Bacteria
Template(s) P50855 (RIBBA_ACTPL); [ Recover all ]
Triggered by HAMAP; MF_01283 (Get profile general information and statistics)

Propagated annotation [?]

Identifier, protein and gene names [?]

Identifier RIBBA
Protein name RecName: Full=Riboflavin biosynthesis protein RibBA;
RecName: Full=3,4-dihydroxy-2-butanone 4-phosphate synthase;
                 Short=DHBP synthase;
RecName: Full=GTP cyclohydrolase-2;
AltName: Full=GTP cyclohydrolase II;
Gene name Name=ribBA;

Comments [?]

FUNCTIONCatalyzes the conversion of D-ribulose 5-phosphate to formate and 3,4-dihydroxy-2-butanone 4-phosphate.
FUNCTIONCatalyzes the conversion of GTP to 2,5-diamino-6- ribosylamino-4(3H)-pyrimidinone 5'-phosphate (DARP), formate and pyrophosphate.
CATALYTIC ACTIVITY Reaction=D-ribulose 5-phosphate = (2S)-2-hydroxy-3-oxobutyl phosphate + formate + H(+); Xref=Rhea:RHEA:18457, ChEBI:CHEBI:15378, ChEBI:CHEBI:15740, ChEBI:CHEBI:58121, ChEBI:CHEBI:58830; EC=;
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=Mg(2+); Xref=ChEBI:CHEBI:18420; Name=Mn(2+); Xref=ChEBI:CHEBI:29035; Note=Binds 2 divalent metal cations per subunit. Magnesium or manganese.;
COFACTOR Name=Zn(2+); Xref=ChEBI:CHEBI:29105; Note=Binds 1 zinc ion per subunit.;
PATHWAYCofactor biosynthesis; riboflavin biosynthesis; 2-hydroxy-3- oxobutyl phosphate from D-ribulose 5-phosphate: step 1/1.
PATHWAYCofactor biosynthesis; riboflavin biosynthesis; 5-amino-6-(D- ribitylamino)uracil from GTP: step 1/4.
SIMILARITYIn the N-terminal section; belongs to the DHBP synthase family.
SIMILARITYIn the C-terminal section; belongs to the GTP cyclohydrolase II family.

Keywords [?]

Gene Ontology [?]

GO:0000287; Molecular function:magnesium ion binding
GO:0003935; Molecular function:GTP cyclohydrolase II activity
GO:0008270; Molecular function:zinc ion binding
GO:0008686; Molecular function:3,4-dihydroxy-2-butanone-4-phosphate synthase activity
GO:0030145; Molecular function:manganese ion binding
GO:0009231; Biological process:riboflavin biosynthetic process

Cross-references [?]

Pfam PF00926; DHBP_synthase; 1;
Pfam PF00925; GTP_cyclohydro2; 1;
NCBIfam TIGR00505; RibA; 1;
NCBIfam TIGR00506; RibB; 1;

Features [?]

From: RIBBA_BACSU (P17620)
Key From To Description Tag Condition FTGroup
BINDING 251 255 /ligand="GTP"
BINDING 294 296 /ligand="GTP"
REGION Nter 199 /note="DHBP synthase"
BINDING 26 27 /ligand="D-ribulose 5-phosphate"
BINDING 138 142 /ligand="D-ribulose 5-phosphate"
REGION 200 Cter /note="GTP cyclohydrolase II"
ACT_SITE 328 328 /note="Proton acceptor; for GTP cyclohydrolase activity" D
ACT_SITE 330 330 /note="Nucleophile; for GTP cyclohydrolase activity" R
BINDING 27 27 /ligand="Mg(2+)"
BINDING 27 27 /ligand="Mg(2+)"
BINDING 141 141 /ligand="Mg(2+)"
BINDING 256 256 /ligand="Zn(2+)"
BINDING 267 267 /ligand="Zn(2+)"
BINDING 269 269 /ligand="Zn(2+)"
BINDING 31 31 /ligand="D-ribulose 5-phosphate"
BINDING 162 162 /ligand="D-ribulose 5-phosphate"
BINDING 272 272 /ligand="GTP"
BINDING 316 316 /ligand="GTP"
BINDING 351 351 /ligand="GTP"
BINDING 356 356 /ligand="GTP"
SITE 124 124 /note="Essential for DHBP synthase activity" H
SITE 162 162 /note="Essential for DHBP synthase activity" E

Additional information [?]

Size range 388-425 amino acids
Related rules MF_00178
Fusion Nter: None Cter: <Unknown>
Comments RibA and RibB are not fused in some organisms (see MF_00179 for RibA and MF_00180 for RibB). Fused with an unknown C-terminal domain in SYNY3.

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