ID RIBBA_SYNWW Reviewed; 398 AA. AC Q0AXM5; DT 05-FEB-2008, integrated into UniProtKB/Swiss-Prot. DT 17-OCT-2006, sequence version 1. DT 02-SEP-2026, entry version 112. 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}; GN OrderedLocusNames=Swol_1220; OS Syntrophomonas wolfei subsp. wolfei (strain DSM 2245B / Goettingen). OC Bacteria; Bacillati; Bacillota; Clostridia; Eubacteriales; OC Syntrophomonadaceae; Syntrophomonas. OX NCBI_TaxID=335541; RN [1] RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. RC STRAIN=DSM 2245B / Goettingen; RX PubMed=21966920; DOI=10.1111/j.1462-2920.2010.02237.x; RA Sieber J.R., Sims D.R., Han C., Kim E., Lykidis A., Lapidus A.L., RA McDonnald E., Rohlin L., Culley D.E., Gunsalus R., McInerney M.J.; RT "The genome of Syntrophomonas wolfei: new insights into syntrophic RT metabolism and biohydrogen production."; RL Environ. Microbiol. 12:2289-2301(2010). 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; CP000448; ABI68529.1; -; Genomic_DNA. DR RefSeq; WP_011640632.1; NC_008346.1. DR AlphaFoldDB; Q0AXM5; -. DR SMR; Q0AXM5; -. DR STRING; 335541.Swol_1220; -. DR KEGG; swo:Swol_1220; -. DR eggNOG; COG0108; Bacteria. DR eggNOG; COG0807; Bacteria. DR HOGENOM; CLU_020273_1_2_9; -. DR OrthoDB; 9793111at2; -. DR UniPathway; UPA00275; UER00399. DR UniPathway; UPA00275; UER00400. DR Proteomes; UP000001968; Chromosome. 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:000001; Riboflavin biosynthesis protein RibBA; 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; PRK00393.1; 1. DR NCBIfam; NF006803; PRK09311.1; 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; Reference proteome; KW Riboflavin biosynthesis; Zinc. FT CHAIN 1..398 FT /note="Riboflavin biosynthesis protein RibBA" FT /id="PRO_1000067431" FT REGION 1..199 FT /note="DHBP synthase" FT REGION 200..398 FT /note="GTP cyclohydrolase II" FT ACT_SITE 327 FT /note="Proton acceptor; for GTP cyclohydrolase activity" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01283" FT ACT_SITE 329 FT /note="Nucleophile; for GTP cyclohydrolase activity" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01283" FT BINDING 26..27 FT /ligand="D-ribulose 5-phosphate" FT /ligand_id="ChEBI:CHEBI:58121" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01283" FT BINDING 27 FT /ligand="Mg(2+)" FT /ligand_id="ChEBI:CHEBI:18420" FT /ligand_label="1" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01283" FT BINDING 27 FT /ligand="Mg(2+)" FT /ligand_id="ChEBI:CHEBI:18420" FT /ligand_label="2" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01283" FT BINDING 31 FT /ligand="D-ribulose 5-phosphate" FT /ligand_id="ChEBI:CHEBI:58121" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01283" FT BINDING 138..142 FT /ligand="D-ribulose 5-phosphate" FT /ligand_id="ChEBI:CHEBI:58121" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01283" FT BINDING 141 FT /ligand="Mg(2+)" FT /ligand_id="ChEBI:CHEBI:18420" FT /ligand_label="2" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01283" FT BINDING 162 FT /ligand="D-ribulose 5-phosphate" FT /ligand_id="ChEBI:CHEBI:58121" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01283" FT BINDING 250..254 FT /ligand="GTP" FT /ligand_id="ChEBI:CHEBI:37565" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01283" FT BINDING 255 FT /ligand="Zn(2+)" FT /ligand_id="ChEBI:CHEBI:29105" FT /ligand_note="catalytic" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01283" FT BINDING 266 FT /ligand="Zn(2+)" FT /ligand_id="ChEBI:CHEBI:29105" FT /ligand_note="catalytic" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01283" FT BINDING 268 FT /ligand="Zn(2+)" FT /ligand_id="ChEBI:CHEBI:29105" FT /ligand_note="catalytic" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01283" FT BINDING 271 FT /ligand="GTP" FT /ligand_id="ChEBI:CHEBI:37565" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01283" FT BINDING 293..295 FT /ligand="GTP" FT /ligand_id="ChEBI:CHEBI:37565" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01283" FT BINDING 315 FT /ligand="GTP" FT /ligand_id="ChEBI:CHEBI:37565" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01283" FT BINDING 350 FT /ligand="GTP" FT /ligand_id="ChEBI:CHEBI:37565" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01283" FT BINDING 355 FT /ligand="GTP" FT /ligand_id="ChEBI:CHEBI:37565" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01283" FT SITE 124 FT /note="Essential for DHBP synthase activity" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01283" FT SITE 162 FT /note="Essential for DHBP synthase activity" FT /evidence="ECO:0000255|HAMAP-Rule:MF_01283" SQ SEQUENCE 398 AA; 44443 MW; 90A6358014178453 CRC64; MFSSIEEVIQ DIKEGKMIVL VDDEDRENEG DVIIAAEKAG PEAINFMATH AKGLICMPII GERLDELEIH DMVTENTDNH ETAFTVTVDY RGTTTGISAF ERAATVKALI DSVSKPSDFR KPGHIFPLRY REGGVLRRAG HTEGSIDLTR LAGLYPAAVI CEVMNEDGTM ARLPQLLEFA RQHNLKLASI ADLIEYRRRK EKLVVRVTDA QLPTMYGDFV AVAYESLLDN KGHIALVKGE WEEDEPILVR VHSECLTGDV FGSRRCDCGE QLETAMSMIA SEGKGVLLYM RQEGRGIGLL NKIKAYKLQD NGRDTVEANL ELGFPADLRD YGIGAQILVD LGVRKMRLMT NNPKKIRGLE GYGLEVVERV AIEMPHKPEN TRYLRTKKEK MGHLLASL //