ID   GCH3_PYRAE              Reviewed;         221 AA.
AC   Q8ZU20;
DT   13-DEC-2002, integrated into UniProtKB/Swiss-Prot.
DT   01-MAR-2002, sequence version 1.
DT   25-MAY-2022, entry version 90.
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=PAE2984;
OS   Pyrobaculum aerophilum (strain ATCC 51768 / DSM 7523 / JCM 9630 / CIP
OS   104966 / NBRC 100827 / IM2).
OC   Archaea; Crenarchaeota; Thermoprotei; Thermoproteales; Thermoproteaceae;
OC   Pyrobaculum.
OX   NCBI_TaxID=178306;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 51768 / DSM 7523 / JCM 9630 / CIP 104966 / NBRC 100827 / IM2;
RX   PubMed=11792869; DOI=10.1073/pnas.241636498;
RA   Fitz-Gibbon S.T., Ladner H., Kim U.-J., Stetter K.O., Simon M.I.,
RA   Miller J.H.;
RT   "Genome sequence of the hyperthermophilic crenarchaeon Pyrobaculum
RT   aerophilum.";
RL   Proc. Natl. Acad. Sci. U.S.A. 99:984-989(2002).
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; AE009441; AAL64588.1; -; Genomic_DNA.
DR   AlphaFoldDB; Q8ZU20; -.
DR   SMR; Q8ZU20; -.
DR   STRING; 178306.PAE2984; -.
DR   EnsemblBacteria; AAL64588; AAL64588; PAE2984.
DR   KEGG; pai:PAE2984; -.
DR   PATRIC; fig|178306.9.peg.2239; -.
DR   eggNOG; arCOG04202; Archaea.
DR   HOGENOM; CLU_080076_0_0_2; -.
DR   InParanoid; Q8ZU20; -.
DR   OMA; THVTRAN; -.
DR   Proteomes; UP000002439; 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; 2.
DR   PIRSF; PIRSF009265; GTP_cyclohydro_3; 1.
DR   SUPFAM; SSF55073; SSF55073; 1.
PE   3: Inferred from homology;
KW   GTP-binding; Hydrolase; Nucleotide-binding; Reference proteome.
FT   CHAIN           1..221
FT                   /note="GTP cyclohydrolase III"
FT                   /id="PRO_0000145757"
SQ   SEQUENCE   221 AA;  24462 MW;  2BC716EA9A596C02 CRC64;
     MHKITLIRLR GYREWTESLG PRREHIIQTV QAKIHSALWK YFTSIGALPH HLRYDFSLAL
     TTNIETGRVG EVVAKIKRIS PVDVEFCEGV GRTPREAYEN CGATPGESAG VSVVAHMDVV
     DSTAATNKNG PLYVYRLIQR TISTIDSGCE NLGCLAFYLG GDNIMLLLPN VDAIYQVLRD
     VELSVRVGVG VAKKPYNAFV KATRGLDYMR VKGRVGVKVV K