ID   GCH3_NATPD              Reviewed;         253 AA.
AC   Q3INZ0;
DT   15-JAN-2008, integrated into UniProtKB/Swiss-Prot.
DT   08-NOV-2005, sequence version 1.
DT   25-MAY-2022, entry version 89.
DE   RecName: Full=GTP cyclohydrolase III {ECO:0000255|HAMAP-Rule:MF_00608};
DE            EC=3.5.4.29 {ECO:0000255|HAMAP-Rule:MF_00608};
GN   Name=gch3 {ECO:0000255|HAMAP-Rule:MF_00608}; OrderedLocusNames=NP_4142A;
OS   Natronomonas pharaonis (strain ATCC 35678 / DSM 2160 / CIP 103997 / JCM
OS   8858 / NBRC 14720 / NCIMB 2260 / Gabara) (Halobacterium pharaonis).
OC   Archaea; Euryarchaeota; Stenosarchaea group; Halobacteria; Halobacteriales;
OC   Haloarculaceae; Natronomonas.
OX   NCBI_TaxID=348780;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 35678 / DSM 2160 / CIP 103997 / JCM 8858 / NBRC 14720 / NCIMB
RC   2260 / Gabara;
RX   PubMed=16169924; DOI=10.1101/gr.3952905;
RA   Falb M., Pfeiffer F., Palm P., Rodewald K., Hickmann V., Tittor J.,
RA   Oesterhelt D.;
RT   "Living with two extremes: conclusions from the genome sequence of
RT   Natronomonas pharaonis.";
RL   Genome Res. 15:1336-1343(2005).
CC   -!- FUNCTION: Catalyzes the formation of 2-amino-5-formylamino-6-
CC       ribofuranosylamino-4(3H)-pyrimidinone ribonucleotide monophosphate and
CC       inorganic phosphate from GTP. Also has an independent pyrophosphate
CC       phosphohydrolase activity. {ECO:0000255|HAMAP-Rule:MF_00608}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=GTP + 3 H2O = 2-amino-5-formylamino-6-(5-phospho-D-
CC         ribosylamino)pyrimidin-4(3H)-one + 2 H(+) + 2 phosphate;
CC         Xref=Rhea:RHEA:22468, ChEBI:CHEBI:15377, ChEBI:CHEBI:15378,
CC         ChEBI:CHEBI:37565, ChEBI:CHEBI:43474, ChEBI:CHEBI:57258; EC=3.5.4.29;
CC         Evidence={ECO:0000255|HAMAP-Rule:MF_00608};
CC   -!- SIMILARITY: Belongs to the archaeal-type GTP cyclohydrolase family.
CC       {ECO:0000255|HAMAP-Rule:MF_00608}.
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DR   EMBL; CR936257; CAI50162.1; -; Genomic_DNA.
DR   RefSeq; WP_011323778.1; NC_007426.1.
DR   AlphaFoldDB; Q3INZ0; -.
DR   SMR; Q3INZ0; -.
DR   STRING; 348780.NP_4142A; -.
DR   PRIDE; Q3INZ0; -.
DR   EnsemblBacteria; CAI50162; CAI50162; NP_4142A.
DR   GeneID; 3702742; -.
DR   KEGG; nph:NP_4142A; -.
DR   eggNOG; arCOG04202; Archaea.
DR   HOGENOM; CLU_080076_0_0_2; -.
DR   OMA; VQIAHID; -.
DR   OrthoDB; 56576at2157; -.
DR   Proteomes; UP000002698; Chromosome.
DR   GO; GO:0005525; F:GTP binding; IEA:UniProtKB-KW.
DR   GO; GO:0043740; F:GTP cyclohydrolase IIa activity; IEA:UniProtKB-EC.
DR   GO; GO:0009058; P:biosynthetic process; IEA:InterPro.
DR   Gene3D; 3.30.70.1230; -; 1.
DR   Gene3D; 3.30.70.270; -; 1.
DR   HAMAP; MF_00608; GTP_cyclohydro_3; 1.
DR   InterPro; IPR007839; GTP_CycHdrlase_3.
DR   InterPro; IPR029787; Nucleotide_cyclase.
DR   InterPro; IPR043128; Rev_trsase/Diguanyl_cyclase.
DR   PANTHER; PTHR42202; PTHR42202; 1.
DR   Pfam; PF05165; GCH_III; 1.
DR   PIRSF; PIRSF009265; GTP_cyclohydro_3; 1.
PE   3: Inferred from homology;
KW   GTP-binding; Hydrolase; Nucleotide-binding; Reference proteome.
FT   CHAIN           1..253
FT                   /note="GTP cyclohydrolase III"
FT                   /id="PRO_1000056696"
SQ   SEQUENCE   253 AA;  27758 MW;  43FCD05ADB54476C CRC64;
     MTNTQVTLVQ IDNYGPWTVT PEPRREVDLQ TLQSRLYADL SQLIGNRMGY VFFTRFDNMV
     AVTNGLDADA HALIQESVGN RYPVTVSLSI GVDSSPAAAL GTATDQLQDA GSAQDKGRTE
     ILRGDPIQPS ERTDTDVQIA HFDVNDATGK YTDQLNEFDS FINIEQGYAE LMRYMRHEND
     SLSFFVGGDN IIAVCDGIDE AAYLDAIEHV NETVGVELKV GVGLDRTAQA AGMAAKHALE
     TCREENTDVE FAR