RIBA_BUCAI
ID RIBA_BUCAI Reviewed; 194 AA.
AC P57359;
DT 01-DEC-2000, integrated into UniProtKB/Swiss-Prot.
DT 01-DEC-2000, sequence version 1.
DT 03-AUG-2022, entry version 97.
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}; OrderedLocusNames=BU271;
OS Buchnera aphidicola subsp. Acyrthosiphon pisum (strain APS) (Acyrthosiphon
OS pisum symbiotic bacterium).
OC Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC Erwiniaceae; Buchnera.
OX NCBI_TaxID=107806;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=APS;
RX PubMed=10993077; DOI=10.1038/35024074;
RA Shigenobu S., Watanabe H., Hattori M., Sakaki Y., Ishikawa H.;
RT "Genome sequence of the endocellular bacterial symbiont of aphids Buchnera
RT sp. APS.";
RL Nature 407:81-86(2000).
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 -!- SUBUNIT: Homodimer. {ECO:0000255|HAMAP-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; BA000003; BAB12981.1; -; Genomic_DNA.
DR RefSeq; NP_240095.1; NC_002528.1.
DR RefSeq; WP_009874225.1; NC_002528.1.
DR AlphaFoldDB; P57359; -.
DR SMR; P57359; -.
DR STRING; 107806.10038946; -.
DR EnsemblBacteria; BAB12981; BAB12981; BAB12981.
DR KEGG; buc:BU271; -.
DR PATRIC; fig|107806.10.peg.281; -.
DR eggNOG; COG0807; Bacteria.
DR HOGENOM; CLU_020273_2_1_6; -.
DR OMA; GQGFILY; -.
DR UniPathway; UPA00275; UER00400.
DR Proteomes; UP000001806; Chromosome.
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.
DR TIGRFAMs; TIGR00505; ribA; 1.
PE 3: Inferred from homology;
KW GTP-binding; Hydrolase; Metal-binding; Nucleotide-binding;
KW Reference proteome; Riboflavin biosynthesis; Zinc.
FT CHAIN 1..194
FT /note="GTP cyclohydrolase-2"
FT /id="PRO_0000151750"
FT ACT_SITE 124
FT /note="Proton acceptor"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179"
FT ACT_SITE 126
FT /note="Nucleophile"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179"
FT BINDING 47..51
FT /ligand="GTP"
FT /ligand_id="ChEBI:CHEBI:37565"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179"
FT BINDING 52
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /ligand_note="catalytic"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179"
FT BINDING 63
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 68
FT /ligand="GTP"
FT /ligand_id="ChEBI:CHEBI:37565"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179"
FT BINDING 90..92
FT /ligand="GTP"
FT /ligand_id="ChEBI:CHEBI:37565"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179"
FT BINDING 112
FT /ligand="GTP"
FT /ligand_id="ChEBI:CHEBI:37565"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179"
FT BINDING 147
FT /ligand="GTP"
FT /ligand_id="ChEBI:CHEBI:37565"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179"
FT BINDING 152
FT /ligand="GTP"
FT /ligand_id="ChEBI:CHEBI:37565"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179"
SQ SEQUENCE 194 AA; 21893 MW; DA45422AFEFEF0B8 CRC64;
MQLIEKAMLP TPWGNFLIFG FEEKKNGKNH VALVYGDIKT NTPTLSRVHS ECLTGDAFFS
LRCDCGSQLE MSMKRISQEG SGVLIYHRQE GRNIGLLNKI KAYALQDRGL DTVQANQKLG
FSADERDFSL CADIFNILNI KKIRLLTNNP FKVQMLSDAG INIVERVPLI VKKNPKNAYY
LKTKAEKMGH LLSE
