RIBA_ACIBT
ID RIBA_ACIBT Reviewed; 200 AA.
AC A3M9B0;
DT 24-MAR-2009, integrated into UniProtKB/Swiss-Prot.
DT 02-SEP-2008, sequence version 2.
DT 03-AUG-2022, entry version 84.
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=A1S_3107;
OS Acinetobacter baumannii (strain ATCC 17978 / CIP 53.77 / LMG 1025 / NCDC
OS KC755 / 5377).
OC Bacteria; Proteobacteria; Gammaproteobacteria; Moraxellales; Moraxellaceae;
OC Acinetobacter; Acinetobacter calcoaceticus/baumannii complex.
OX NCBI_TaxID=400667;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=ATCC 17978 / CIP 53.77 / LMG 1025 / NCDC KC755 / 5377;
RX PubMed=17344419; DOI=10.1101/gad.1510307;
RA Smith M.G., Gianoulis T.A., Pukatzki S., Mekalanos J.J., Ornston L.N.,
RA Gerstein M., Snyder M.;
RT "New insights into Acinetobacter baumannii pathogenesis revealed by high-
RT density pyrosequencing and transposon mutagenesis.";
RL Genes Dev. 21:601-614(2007).
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; CP000521; ABO13504.2; -; Genomic_DNA.
DR RefSeq; WP_001121174.1; NZ_CP053098.1.
DR AlphaFoldDB; A3M9B0; -.
DR SMR; A3M9B0; -.
DR GeneID; 60878108; -.
DR GeneID; 66395712; -.
DR KEGG; acb:A1S_3107; -.
DR HOGENOM; CLU_020273_2_1_6; -.
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.
DR TIGRFAMs; TIGR00505; ribA; 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_1000098261"
FT ACT_SITE 127
FT /note="Proton acceptor"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179"
FT ACT_SITE 129
FT /note="Nucleophile"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179"
FT BINDING 50..54
FT /ligand="GTP"
FT /ligand_id="ChEBI:CHEBI:37565"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179"
FT BINDING 55
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /ligand_note="catalytic"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179"
FT BINDING 66
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="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /ligand_note="catalytic"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179"
FT BINDING 71
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 115
FT /ligand="GTP"
FT /ligand_id="ChEBI:CHEBI:37565"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179"
FT BINDING 150
FT /ligand="GTP"
FT /ligand_id="ChEBI:CHEBI:37565"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179"
FT BINDING 155
FT /ligand="GTP"
FT /ligand_id="ChEBI:CHEBI:37565"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179"
SQ SEQUENCE 200 AA; 22314 MW; 907A0CCA9486F656 CRC64;
MPIEFIATSK LPTAFGEFNI SVFQDPVTGE EHVALSKGLE NPPTGPVLVR VHSECLTGDA
FASLKCDCGP QLQATQKLIN EAGQGVILYL RQEGRGIGLT NKIRAYALQD QGHDTVDANL
LLNLPADARR YDMCSIMLDH LKVKEVKLIT NNPLKIQALK DQGINVVDRV PLTVGRNPFN
EQYLKTKRER MDHLYQKDDF
