ID RIBA_SHEB5 Reviewed; 204 AA. AC A3D367; DT 15-JAN-2008, integrated into UniProtKB/Swiss-Prot. DT 20-MAR-2007, sequence version 1. DT 04-NOV-2026, entry version 89. 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}; GN Name=ribA {ECO:0000255|HAMAP-Rule:MF_00179}; GN OrderedLocusNames=Sbal_1668; OS Shewanella baltica (strain OS155 / ATCC BAA-1091). OC Bacteria; Pseudomonadati; Pseudomonadota; Gammaproteobacteria; OC Alteromonadales; Shewanellaceae; Shewanella. OX NCBI_TaxID=325240; RN [1] RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. RC STRAIN=OS155 / ATCC BAA-1091; RG US DOE Joint Genome Institute; RA Copeland A., Lucas S., Lapidus A., Barry K., Detter J.C., RA Glavina del Rio T., Hammon N., Israni S., Dalin E., Tice H., Pitluck S., RA Sims D.R., Brettin T., Bruce D., Han C., Tapia R., Brainard J., Schmutz J., RA Larimer F., Land M., Hauser L., Kyrpides N., Mikhailova N., Brettar I., RA Klappenbach J., Konstantinidis K., Rodrigues J., Tiedje J., Richardson P.; RT "Complete sequence of chromosome of Shewanella baltica OS155."; RL Submitted (FEB-2007) to the EMBL/GenBank/DDBJ databases. 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 + 2 phosphate + 3 H(+); 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; Evidence={ECO:0000255|HAMAP- CC 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}. CC --------------------------------------------------------------------------- CC Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms CC Distributed under the Creative Commons Attribution (CC BY 4.0) License CC --------------------------------------------------------------------------- DR EMBL; CP000563; ABN61180.1; -; Genomic_DNA. DR RefSeq; WP_011846503.1; NC_009052.1. DR AlphaFoldDB; A3D367; -. DR SMR; A3D367; -. DR STRING; 325240.Sbal_1668; -. DR KEGG; sbl:Sbal_1668; -. DR HOGENOM; CLU_020273_2_1_6; -. DR OMA; AAHMIHG; -. DR OrthoDB; 9793111at2; -. DR UniPathway; UPA00275; UER00400. DR Proteomes; UP000001557; Chromosome. DR GO; GO:0005829; C:cytosol; IEA:TreeGrafter. 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 FunFam; 3.40.50.10990:FF:000002; GTP cyclohydrolase-2; 1. DR Gene3D; 3.40.50.10990; GTP cyclohydrolase II; 1. DR HAMAP; MF_00179; RibA; 1. DR InterPro; IPR032677; GTP_cyclohydro_II. DR InterPro; IPR000926; RibA. DR InterPro; IPR036144; RibA-like_sf. DR NCBIfam; NF001591; ribA; 1. DR NCBIfam; TIGR00505; ribA; 1. DR PANTHER; PTHR21327:SF18; 3,4-DIHYDROXY-2-BUTANONE 4-PHOSPHATE SYNTHASE; 1. DR PANTHER; PTHR21327; GTP CYCLOHYDROLASE II-RELATED; 1. DR Pfam; PF00925; GTP_cyclohydro2; 1. DR SUPFAM; SSF142695; RibA-like; 1. PE 3: Inferred from homology; KW GTP-binding; Hydrolase; Metal-binding; Nucleotide-binding; KW Reference proteome; Riboflavin biosynthesis; Zinc. FT CHAIN 1..204 FT /note="GTP cyclohydrolase-2" FT /id="PRO_1000040579" FT ACT_SITE 126 FT /note="Proton acceptor" FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179" FT ACT_SITE 128 FT /note="Nucleophile" FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179" FT BINDING 49..53 FT /ligand="GTP" FT /ligand_id="ChEBI:CHEBI:37565" FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179" FT BINDING 54 FT /ligand="Zn(2+)" FT /ligand_id="ChEBI:CHEBI:29105" FT /ligand_note="catalytic" FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179" FT BINDING 65 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 70 FT /ligand="GTP" FT /ligand_id="ChEBI:CHEBI:37565" FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179" FT BINDING 92..94 FT /ligand="GTP" FT /ligand_id="ChEBI:CHEBI:37565" FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179" FT BINDING 114 FT /ligand="GTP" FT /ligand_id="ChEBI:CHEBI:37565" FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179" FT BINDING 149 FT /ligand="GTP" FT /ligand_id="ChEBI:CHEBI:37565" FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179" FT BINDING 154 FT /ligand="GTP" FT /ligand_id="ChEBI:CHEBI:37565" FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179" SQ SEQUENCE 204 AA; 22997 MW; 81F61281BD8FAA24 CRC64; MSIKYVATSK LPTPWGVFAM HGFEDTESGK EHVALTFGTL SADEPVLGRI HSECLTGDAL FSLRCDCGFQ LQAAMQNIAE TGSGFILYLR QEGRGIGLLN KIRAYELQDK GANTVEANEQ LGFEADMRKY DMIKPILEQI GVKHVRLMTN NPRKVKAMKE FGIEVVERVP LQVGKNRYNE AYLKTKSTEL GHMMSEYHFM DENK //