ID   RIBA_SULMU              Reviewed;         141 AA.
AC   O68248;
DT   01-DEC-2000, integrated into UniProtKB/Swiss-Prot.
DT   01-AUG-1998, sequence version 1.
DT   03-AUG-2022, entry version 72.
DE   RecName: Full=GTP cyclohydrolase-2;
DE            EC=3.5.4.25;
DE   AltName: Full=GTP cyclohydrolase II;
DE   Flags: Fragment;
GN   Name=ribA;
OS   Sulfurospirillum multivorans (Dehalospirillum multivorans).
OC   Bacteria; Proteobacteria; Epsilonproteobacteria; Campylobacterales;
OC   Sulfurospirillaceae; Sulfurospirillum.
OX   NCBI_TaxID=66821;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=9696761; DOI=10.1128/jb.180.16.4140-4145.1998;
RA   Neumann A., Wohlfarth G., Diekert G.;
RT   "Tetrachloroethene dehalogenase from Dehalospirillum multivorans: cloning,
RT   sequencing of the encoding genes, and expression of the pceA gene in
RT   Escherichia coli.";
RL   J. Bacteriol. 180:4140-4145(1998).
CC   -!- FUNCTION: Catalyzes the conversion of GTP to 2,5-diamino-6-
CC       ribosylamino-4(3H)-pyrimidinone 5'-phosphate (DARP), formate and
CC       pyrophosphate. {ECO:0000250}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=GTP + 4 H2O = 2,5-diamino-6-hydroxy-4-(5-phosphoribosylamino)-
CC         pyrimidine + formate + 3 H(+) + 2 phosphate; Xref=Rhea:RHEA:23704,
CC         ChEBI:CHEBI:15377, ChEBI:CHEBI:15378, ChEBI:CHEBI:15740,
CC         ChEBI:CHEBI:37565, ChEBI:CHEBI:43474, ChEBI:CHEBI:58614; EC=3.5.4.25;
CC   -!- COFACTOR:
CC       Name=Zn(2+); Xref=ChEBI:CHEBI:29105; Evidence={ECO:0000250};
CC       Note=Binds 1 zinc ion per subunit. {ECO:0000250};
CC   -!- PATHWAY: Cofactor biosynthesis; riboflavin biosynthesis; 5-amino-6-(D-
CC       ribitylamino)uracil from GTP: step 1/4.
CC   -!- SIMILARITY: Belongs to the GTP cyclohydrolase II family. {ECO:0000305}.
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DR   EMBL; AF022812; AAC60784.1; -; Genomic_DNA.
DR   AlphaFoldDB; O68248; -.
DR   SMR; O68248; -.
DR   STRING; 1150621.SMUL_1527; -.
DR   UniPathway; UPA00275; UER00400.
DR   GO; GO:0005525; F:GTP binding; IEA:UniProtKB-KW.
DR   GO; GO:0003935; F:GTP cyclohydrolase II activity; IEA:UniProtKB-EC.
DR   GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR   GO; GO:0009231; P:riboflavin biosynthetic process; IEA:UniProtKB-UniPathway.
DR   CDD; cd00641; GTP_cyclohydro2; 1.
DR   Gene3D; 3.40.50.10990; -; 1.
DR   InterPro; IPR032677; GTP_cyclohydro_II.
DR   InterPro; IPR000926; RibA.
DR   InterPro; IPR036144; RibA-like_sf.
DR   Pfam; PF00925; GTP_cyclohydro2; 1.
DR   SUPFAM; SSF142695; SSF142695; 1.
DR   TIGRFAMs; TIGR00505; ribA; 1.
PE   3: Inferred from homology;
KW   GTP-binding; Hydrolase; Metal-binding; Nucleotide-binding;
KW   Riboflavin biosynthesis; Zinc.
FT   CHAIN           <1..141
FT                   /note="GTP cyclohydrolase-2"
FT                   /id="PRO_0000151753"
FT   ACT_SITE        75
FT                   /note="Proton acceptor"
FT                   /evidence="ECO:0000255"
FT   ACT_SITE        77
FT                   /note="Nucleophile"
FT                   /evidence="ECO:0000250"
FT   BINDING         <1..3
FT                   /ligand="GTP"
FT                   /ligand_id="ChEBI:CHEBI:37565"
FT                   /evidence="ECO:0000250"
FT   BINDING         4
FT                   /ligand="Zn(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29105"
FT                   /ligand_note="catalytic"
FT                   /evidence="ECO:0000250"
FT   BINDING         15
FT                   /ligand="Zn(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29105"
FT                   /ligand_note="catalytic"
FT                   /evidence="ECO:0000250"
FT   BINDING         17
FT                   /ligand="Zn(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29105"
FT                   /ligand_note="catalytic"
FT                   /evidence="ECO:0000250"
FT   BINDING         20
FT                   /ligand="GTP"
FT                   /ligand_id="ChEBI:CHEBI:37565"
FT                   /evidence="ECO:0000250"
FT   BINDING         41..43
FT                   /ligand="GTP"
FT                   /ligand_id="ChEBI:CHEBI:37565"
FT                   /evidence="ECO:0000250"
FT   BINDING         63
FT                   /ligand="GTP"
FT                   /ligand_id="ChEBI:CHEBI:37565"
FT                   /evidence="ECO:0000250"
FT   BINDING         98
FT                   /ligand="GTP"
FT                   /ligand_id="ChEBI:CHEBI:37565"
FT                   /evidence="ECO:0000250"
FT   BINDING         103
FT                   /ligand="GTP"
FT                   /ligand_id="ChEBI:CHEBI:37565"
FT                   /evidence="ECO:0000250"
FT   NON_TER         1
SQ   SEQUENCE   141 AA;  16138 MW;  02B1FB3078FC56E4 CRC64;
     HSECLTGDAL GSLKCDCGEQ LEFALQNISL LGGMIIYLRQ EGRNIGLFNK VNAYALQDQG
     FDTIEANHQL GFKSDERSYE VVETILEHFK IDKIRLLTNN PKKMSCLKNI MIIERWPIII
     PSNNHNVDYL KTKKEMMGHL L