RIBA_PHOPO
ID RIBA_PHOPO Reviewed; 200 AA.
AC P51618;
DT 01-OCT-1996, integrated into UniProtKB/Swiss-Prot.
DT 01-OCT-1996, sequence version 1.
DT 03-AUG-2022, entry version 75.
DE RecName: Full=GTP cyclohydrolase-2 {ECO:0000255|HAMAP-Rule:MF_00179};
DE EC=3.5.4.25 {ECO:0000255|HAMAP-Rule:MF_00179};
DE AltName: Full=GTP cyclohydrolase II {ECO:0000255|HAMAP-Rule:MF_00179};
DE AltName: Full=RIBIV;
GN Name=ribA {ECO:0000255|HAMAP-Rule:MF_00179};
OS Photobacterium phosphoreum.
OC Bacteria; Proteobacteria; Gammaproteobacteria; Vibrionales; Vibrionaceae;
OC Photobacterium.
OX NCBI_TaxID=659;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC STRAIN=DSM 2167 / CIP 104260 / LMG 4231 / NCIMB 844;
RX PubMed=8144477; DOI=10.1128/jb.176.7.2100-2104.1994;
RA Lee C.Y., O'Kane D.J., Meighen E.A.;
RT "Riboflavin synthesis genes are linked with the lux operon of
RT Photobacterium phosphoreum.";
RL J. Bacteriol. 176:2100-2104(1994).
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:0000255|HAMAP-Rule:MF_00179}.
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 Evidence={ECO:0000255|HAMAP-Rule:MF_00179};
CC -!- COFACTOR:
CC Name=Zn(2+); Xref=ChEBI:CHEBI:29105;
CC Evidence={ECO:0000255|HAMAP-Rule:MF_00179};
CC Note=Binds 1 zinc ion per subunit. {ECO:0000255|HAMAP-Rule:MF_00179};
CC -!- PATHWAY: Cofactor biosynthesis; riboflavin biosynthesis; 5-amino-6-(D-
CC ribitylamino)uracil from GTP: step 1/4. {ECO:0000255|HAMAP-
CC Rule:MF_00179}.
CC -!- SIMILARITY: Belongs to the GTP cyclohydrolase II family.
CC {ECO:0000255|HAMAP-Rule:MF_00179}.
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DR EMBL; L11391; AAA25631.1; -; Genomic_DNA.
DR AlphaFoldDB; P51618; -.
DR SMR; P51618; -.
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-UniRule.
DR GO; GO:0008270; F:zinc ion binding; IEA:UniProtKB-UniRule.
DR GO; GO:0009231; P:riboflavin biosynthetic process; IEA:UniProtKB-UniRule.
DR CDD; cd00641; GTP_cyclohydro2; 1.
DR Gene3D; 3.40.50.10990; -; 1.
DR HAMAP; MF_00179; RibA; 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.
PE 3: Inferred from homology;
KW GTP-binding; Hydrolase; Metal-binding; Nucleotide-binding;
KW Riboflavin biosynthesis; Zinc.
FT CHAIN 1..200
FT /note="GTP cyclohydrolase-2"
FT /id="PRO_0000151767"
FT ACT_SITE 128
FT /note="Proton acceptor"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179"
FT ACT_SITE 130
FT /note="Nucleophile"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179"
FT BINDING 51..55
FT /ligand="GTP"
FT /ligand_id="ChEBI:CHEBI:37565"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179"
FT BINDING 56
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /ligand_note="catalytic"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179"
FT BINDING 67
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /ligand_note="catalytic"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179"
FT BINDING 69
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /ligand_note="catalytic"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179"
FT BINDING 72
FT /ligand="GTP"
FT /ligand_id="ChEBI:CHEBI:37565"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179"
FT BINDING 93..95
FT /ligand="GTP"
FT /ligand_id="ChEBI:CHEBI:37565"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179"
FT BINDING 116
FT /ligand="GTP"
FT /ligand_id="ChEBI:CHEBI:37565"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179"
FT BINDING 151
FT /ligand="GTP"
FT /ligand_id="ChEBI:CHEBI:37565"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179"
FT BINDING 156
FT /ligand="GTP"
FT /ligand_id="ChEBI:CHEBI:37565"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179"
SQ SEQUENCE 200 AA; 22358 MW; 0EDE538D15FEEE24 CRC64;
MVNVRERVSL KVGINSNAPA ELLSFNGLES GKEHIALIFK DAYKAFVPLV RMHSECLTGD
GFHSTRCDCG EQLDETIEIM AELGGIILYL RQEGRWGLGL YNKIDAYKLQ SQGMDTYEAN
NHLGFDDDLR EFSEAAQMLT ALGIKDIRLV TNNPKKIKDL QQNGINIVEV VGTKAHLKEG
NEGYLKAKAS HGRHCFNFDK
