ID RIBBA_STAAN Reviewed; 393 AA. AC Q7A511; DT 22-NOV-2005, integrated into UniProtKB/Swiss-Prot. DT 05-JUL-2004, sequence version 1. DT 04-NOV-2026, entry version 125. DE RecName: Full=Riboflavin biosynthesis protein RibBA {ECO:0000255|HAMAP-Rule:MF_01283}; DE Includes: DE RecName: Full=3,4-dihydroxy-2-butanone 4-phosphate synthase {ECO:0000255|HAMAP-Rule:MF_01283}; DE Short=DHBP synthase {ECO:0000255|HAMAP-Rule:MF_01283}; DE EC=4.1.99.12 {ECO:0000255|HAMAP-Rule:MF_01283}; DE Includes: DE RecName: Full=GTP cyclohydrolase-2 {ECO:0000255|HAMAP-Rule:MF_01283}; DE EC=3.5.4.25 {ECO:0000255|HAMAP-Rule:MF_01283}; DE AltName: Full=GTP cyclohydrolase II {ECO:0000255|HAMAP-Rule:MF_01283}; GN Name=ribBA {ECO:0000255|HAMAP-Rule:MF_01283}; Synonyms=ribA; GN OrderedLocusNames=SA1587; OS Staphylococcus aureus (strain N315). OC Bacteria; Bacillati; Bacillota; Bacilli; Caryophanales; Staphylococcaceae; OC Staphylococcus. OX NCBI_TaxID=158879; RN [1] RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. RC STRAIN=N315; RX PubMed=11418146; DOI=10.1016/s0140-6736(00)04403-2; RA Kuroda M., Ohta T., Uchiyama I., Baba T., Yuzawa H., Kobayashi I., Cui L., RA Oguchi A., Aoki K., Nagai Y., Lian J.-Q., Ito T., Kanamori M., RA Matsumaru H., Maruyama A., Murakami H., Hosoyama A., Mizutani-Ui Y., RA Takahashi N.K., Sawano T., Inoue R., Kaito C., Sekimizu K., Hirakawa H., RA Kuhara S., Goto S., Yabuzaki J., Kanehisa M., Yamashita A., Oshima K., RA Furuya K., Yoshino C., Shiba T., Hattori M., Ogasawara N., Hayashi H., RA Hiramatsu K.; RT "Whole genome sequencing of meticillin-resistant Staphylococcus aureus."; RL Lancet 357:1225-1240(2001). CC -!- FUNCTION: Catalyzes the conversion of D-ribulose 5-phosphate to formate CC and 3,4-dihydroxy-2-butanone 4-phosphate. {ECO:0000255|HAMAP- CC Rule:MF_01283}. 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_01283}. CC -!- CATALYTIC ACTIVITY: CC Reaction=D-ribulose 5-phosphate = (2S)-2-hydroxy-3-oxobutyl phosphate + CC formate + H(+); Xref=Rhea:RHEA:18457, ChEBI:CHEBI:15378, CC ChEBI:CHEBI:15740, ChEBI:CHEBI:58121, ChEBI:CHEBI:58830; CC EC=4.1.99.12; Evidence={ECO:0000255|HAMAP-Rule:MF_01283}; 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_01283}; CC -!- COFACTOR: CC Name=Mg(2+); Xref=ChEBI:CHEBI:18420; Evidence={ECO:0000255|HAMAP- CC Rule:MF_01283}; CC Name=Mn(2+); Xref=ChEBI:CHEBI:29035; Evidence={ECO:0000255|HAMAP- CC Rule:MF_01283}; CC Note=Binds 2 divalent metal cations per subunit. Magnesium or CC manganese. {ECO:0000255|HAMAP-Rule:MF_01283}; CC -!- COFACTOR: CC Name=Zn(2+); Xref=ChEBI:CHEBI:29105; Evidence={ECO:0000255|HAMAP- CC Rule:MF_01283}; CC Note=Binds 1 zinc ion per subunit. {ECO:0000255|HAMAP-Rule:MF_01283}; CC -!- PATHWAY: Cofactor biosynthesis; riboflavin biosynthesis; 2-hydroxy-3- CC oxobutyl phosphate from D-ribulose 5-phosphate: step 1/1. CC {ECO:0000255|HAMAP-Rule:MF_01283}. CC -!- PATHWAY: Cofactor biosynthesis; riboflavin biosynthesis; 5-amino-6-(D- CC ribitylamino)uracil from GTP: step 1/4. {ECO:0000255|HAMAP- CC Rule:MF_01283}. CC -!- SIMILARITY: In the N-terminal section; belongs to the DHBP synthase CC family. {ECO:0000255|HAMAP-Rule:MF_01283}. CC -!- SIMILARITY: In the C-terminal section; belongs to the GTP CC cyclohydrolase II family. {ECO:0000255|HAMAP-Rule:MF_01283}. 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; BA000018; BAB42855.1; -; Genomic_DNA. DR PIR; B89962; B89962. DR RefSeq; WP_001159037.1; NC_002745.2. DR AlphaFoldDB; Q7A511; -. DR SMR; Q7A511; -. DR EnsemblBacteria; BAB42855; BAB42855; BAB42855. DR KEGG; sau:SA1587; -. DR HOGENOM; CLU_020273_1_2_9; -. DR OMA; AAECCQP; -. DR UniPathway; UPA00275; UER00399. DR UniPathway; UPA00275; UER00400. DR GO; GO:0005829; C:cytosol; IEA:TreeGrafter. DR GO; GO:0008686; F:3,4-dihydroxy-2-butanone-4-phosphate synthase activity; IEA:UniProtKB-UniRule. DR GO; GO:0003935; F:GTP cyclohydrolase II activity; IEA:UniProtKB-UniRule. DR GO; GO:0000287; F:magnesium ion binding; IEA:UniProtKB-UniRule. DR GO; GO:0030145; F:manganese ion binding; 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 FunFam; 3.90.870.10:FF:000001; Riboflavin biosynthesis protein RibBA; 1. DR Gene3D; 3.90.870.10; DHBP synthase; 1. DR Gene3D; 3.40.50.10990; GTP cyclohydrolase II; 1. DR HAMAP; MF_00179; RibA; 1. DR HAMAP; MF_00180; RibB; 1. DR HAMAP; MF_01283; RibBA; 1. DR InterPro; IPR017945; DHBP_synth_RibB-like_a/b_dom. DR InterPro; IPR000422; DHBP_synthase_RibB. DR InterPro; IPR032677; GTP_cyclohydro_II. DR InterPro; IPR000926; RibA. DR InterPro; IPR036144; RibA-like_sf. DR InterPro; IPR016299; Riboflavin_synth_RibBA. DR NCBIfam; NF001591; ribA; 1. DR NCBIfam; TIGR00505; ribA; 1. DR NCBIfam; TIGR00506; ribB; 1. DR PANTHER; PTHR21327:SF18; 3,4-DIHYDROXY-2-BUTANONE 4-PHOSPHATE SYNTHASE; 1. DR PANTHER; PTHR21327; GTP CYCLOHYDROLASE II-RELATED; 1. DR Pfam; PF00926; DHBP_synthase; 1. DR Pfam; PF00925; GTP_cyclohydro2; 1. DR PIRSF; PIRSF001259; RibA; 1. DR SUPFAM; SSF142695; RibA-like; 1. DR SUPFAM; SSF55821; YrdC/RibB; 1. PE 3: Inferred from homology; KW GTP-binding; Hydrolase; Lyase; Magnesium; Manganese; Metal-binding; KW Multifunctional enzyme; Nucleotide-binding; Riboflavin biosynthesis; Zinc. FT CHAIN 1..393 FT /note="Riboflavin biosynthesis protein RibBA" FT /id="PRO_0000151735" FT REGION 1..200 FT /note="DHBP synthase" FT REGION 201..393 FT /note="GTP cyclohydrolase II" FT ACT_SITE 325 FT /note="Proton acceptor; for GTP cyclohydrolase activity" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01283" FT ACT_SITE 327 FT /note="Nucleophile; for GTP cyclohydrolase activity" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01283" FT BINDING 27..28 FT /ligand="D-ribulose 5-phosphate" FT /ligand_id="ChEBI:CHEBI:58121" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01283" FT BINDING 28 FT /ligand="Mg(2+)" FT /ligand_id="ChEBI:CHEBI:18420" FT /ligand_label="1" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01283" FT BINDING 28 FT /ligand="Mg(2+)" FT /ligand_id="ChEBI:CHEBI:18420" FT /ligand_label="2" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01283" FT BINDING 32 FT /ligand="D-ribulose 5-phosphate" FT /ligand_id="ChEBI:CHEBI:58121" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01283" FT BINDING 139..143 FT /ligand="D-ribulose 5-phosphate" FT /ligand_id="ChEBI:CHEBI:58121" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01283" FT BINDING 142 FT /ligand="Mg(2+)" FT /ligand_id="ChEBI:CHEBI:18420" FT /ligand_label="2" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01283" FT BINDING 163 FT /ligand="D-ribulose 5-phosphate" FT /ligand_id="ChEBI:CHEBI:58121" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01283" FT BINDING 249..253 FT /ligand="GTP" FT /ligand_id="ChEBI:CHEBI:37565" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01283" FT BINDING 254 FT /ligand="Zn(2+)" FT /ligand_id="ChEBI:CHEBI:29105" FT /ligand_note="catalytic" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01283" FT BINDING 265 FT /ligand="Zn(2+)" FT /ligand_id="ChEBI:CHEBI:29105" FT /ligand_note="catalytic" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01283" FT BINDING 267 FT /ligand="Zn(2+)" FT /ligand_id="ChEBI:CHEBI:29105" FT /ligand_note="catalytic" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01283" FT BINDING 270 FT /ligand="GTP" FT /ligand_id="ChEBI:CHEBI:37565" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01283" FT BINDING 291..293 FT /ligand="GTP" FT /ligand_id="ChEBI:CHEBI:37565" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01283" FT BINDING 313 FT /ligand="GTP" FT /ligand_id="ChEBI:CHEBI:37565" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01283" FT BINDING 348 FT /ligand="GTP" FT /ligand_id="ChEBI:CHEBI:37565" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01283" FT BINDING 353 FT /ligand="GTP" FT /ligand_id="ChEBI:CHEBI:37565" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01283" FT SITE 125 FT /note="Essential for DHBP synthase activity" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01283" FT SITE 163 FT /note="Essential for DHBP synthase activity" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01283" SQ SEQUENCE 393 AA; 44148 MW; 764A49DFDD46792C CRC64; MQFDNIDSAL MALKNGETII VVDDENRENE GDLVAVTEWM NDNTINFMAK EARGLICAPV SKDIAQRLDL VQMVDDNSDI FGTQFTVSID HVDTTTGISA YERTLTAKKL IDPSSEAKDF NRPGHLFPLV AQDKGVLARN GHTEAAVDLA KLTGAKPAGV ICEIMNDDGT MAKGQDLQNF KEKHQLKMIT IDDLIEYRKK LEPEIEFKAK VKMPTDFGTF DMYGFKATYT DEEIVVLTKG AIRQHENVRL HSACLTGDIF HSQRCDCGAQ LESSMKYINE HGGMIIYLPQ EGRGIGLLNK LRAYELIEQG YDTVTANLAL GFDEDLRDYH IAAQILKYFN IEHINLLSNN PSKFEGLKQY GIDIAERIEV IVPETVHNHD YMVTKKIKMG HLI //