ID   RISA_BUCBP              Reviewed;         212 AA.
AC   Q89AX1;
DT   14-NOV-2003, integrated into UniProtKB/Swiss-Prot.
DT   01-JUN-2003, sequence version 1.
DT   03-AUG-2022, entry version 107.
DE   RecName: Full=Riboflavin synthase;
DE            Short=RS;
DE            EC=2.5.1.9;
GN   Name=ribE; OrderedLocusNames=bbp_107;
OS   Buchnera aphidicola subsp. Baizongia pistaciae (strain Bp).
OC   Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC   Erwiniaceae; Buchnera.
OX   NCBI_TaxID=224915;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=Bp;
RX   PubMed=12522265; DOI=10.1073/pnas.0235981100;
RA   van Ham R.C.H.J., Kamerbeek J., Palacios C., Rausell C., Abascal F.,
RA   Bastolla U., Fernandez J.M., Jimenez L., Postigo M., Silva F.J.,
RA   Tamames J., Viguera E., Latorre A., Valencia A., Moran F., Moya A.;
RT   "Reductive genome evolution in Buchnera aphidicola.";
RL   Proc. Natl. Acad. Sci. U.S.A. 100:581-586(2003).
CC   -!- FUNCTION: Catalyzes the dismutation of two molecules of 6,7-dimethyl-8-
CC       ribityllumazine, resulting in the formation of riboflavin and 5-amino-
CC       6-(D-ribitylamino)uracil. {ECO:0000250}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=2 6,7-dimethyl-8-(1-D-ribityl)lumazine + H(+) = 5-amino-6-(D-
CC         ribitylamino)uracil + riboflavin; Xref=Rhea:RHEA:20772,
CC         ChEBI:CHEBI:15378, ChEBI:CHEBI:15934, ChEBI:CHEBI:57986,
CC         ChEBI:CHEBI:58201; EC=2.5.1.9;
CC   -!- PATHWAY: Cofactor biosynthesis; riboflavin biosynthesis; riboflavin
CC       from 2-hydroxy-3-oxobutyl phosphate and 5-amino-6-(D-
CC       ribitylamino)uracil: step 2/2.
CC   -!- SUBUNIT: Homotrimer. {ECO:0000250}.
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DR   EMBL; AE016826; AAO26841.1; -; Genomic_DNA.
DR   AlphaFoldDB; Q89AX1; -.
DR   SMR; Q89AX1; -.
DR   STRING; 224915.bbp_107; -.
DR   PRIDE; Q89AX1; -.
DR   EnsemblBacteria; AAO26841; AAO26841; bbp_107.
DR   KEGG; bab:bbp_107; -.
DR   eggNOG; COG0307; Bacteria.
DR   HOGENOM; CLU_034388_0_1_6; -.
DR   OMA; HILSGHV; -.
DR   UniPathway; UPA00275; UER00405.
DR   Proteomes; UP000000601; Chromosome.
DR   GO; GO:0004746; F:riboflavin synthase activity; IEA:UniProtKB-EC.
DR   GO; GO:0009231; P:riboflavin biosynthetic process; IEA:UniProtKB-UniPathway.
DR   CDD; cd00402; Riboflavin_synthase_like; 1.
DR   Gene3D; 2.40.30.20; -; 2.
DR   InterPro; IPR023366; ATP_synth_asu-like_sf.
DR   InterPro; IPR001783; Lumazine-bd.
DR   InterPro; IPR026017; Lumazine-bd_dom.
DR   InterPro; IPR017938; Riboflavin_synthase-like_b-brl.
DR   PANTHER; PTHR21098; PTHR21098; 1.
DR   Pfam; PF00677; Lum_binding; 2.
DR   PIRSF; PIRSF000498; Riboflavin_syn_A; 1.
DR   SUPFAM; SSF63380; SSF63380; 2.
DR   TIGRFAMs; TIGR00187; ribE; 1.
DR   PROSITE; PS51177; LUMAZINE_BIND; 2.
PE   3: Inferred from homology;
KW   Reference proteome; Repeat; Riboflavin biosynthesis; Transferase.
FT   CHAIN           1..212
FT                   /note="Riboflavin synthase"
FT                   /id="PRO_0000068162"
FT   REPEAT          1..97
FT                   /note="Lumazine-binding 1"
FT   REPEAT          98..195
FT                   /note="Lumazine-binding 2"
FT   BINDING         4..6
FT                   /ligand="2,4-dihydroxypteridine"
FT                   /ligand_id="ChEBI:CHEBI:16489"
FT                   /ligand_label="1"
FT                   /evidence="ECO:0000250|UniProtKB:Q2YN92"
FT   BINDING         48..50
FT                   /ligand="2,4-dihydroxypteridine"
FT                   /ligand_id="ChEBI:CHEBI:16489"
FT                   /ligand_label="2"
FT                   /ligand_note="ligand shared between two trimeric partners"
FT                   /evidence="ECO:0000250|UniProtKB:Q2YN92"
FT   BINDING         62..67
FT                   /ligand="2,4-dihydroxypteridine"
FT                   /ligand_id="ChEBI:CHEBI:16489"
FT                   /ligand_label="2"
FT                   /ligand_note="ligand shared between two trimeric partners"
FT                   /evidence="ECO:0000250|UniProtKB:P0AFU8"
FT   BINDING         101..103
FT                   /ligand="2,4-dihydroxypteridine"
FT                   /ligand_id="ChEBI:CHEBI:16489"
FT                   /ligand_label="2"
FT                   /ligand_note="ligand shared between two trimeric partners"
FT                   /evidence="ECO:0000250|UniProtKB:Q2YN92"
FT   BINDING         137
FT                   /ligand="2,4-dihydroxypteridine"
FT                   /ligand_id="ChEBI:CHEBI:16489"
FT                   /ligand_label="2"
FT                   /ligand_note="ligand shared between two trimeric partners"
FT                   /note="in other chain"
FT                   /evidence="ECO:0000250|UniProtKB:Q2YN92"
FT   BINDING         146..148
FT                   /ligand="2,4-dihydroxypteridine"
FT                   /ligand_id="ChEBI:CHEBI:16489"
FT                   /ligand_label="1"
FT                   /evidence="ECO:0000250|UniProtKB:Q2YN92"
FT   BINDING         160..165
FT                   /ligand="2,4-dihydroxypteridine"
FT                   /ligand_id="ChEBI:CHEBI:16489"
FT                   /ligand_label="1"
FT                   /evidence="ECO:0000250|UniProtKB:Q2YN92"
SQ   SEQUENCE   212 AA;  23742 MW;  C0C426970FF36138 CRC64;
     MFTGIVRGLG KVVKILKEKK ISQWEVETSN ELVKNLMLGA SISCNGCCLT VRNIFRTIFC
     VDIVEETLRS TSLNTIIVGQ YINLERSIKF GEEVGGHLVS GHIITTGVVS DKKELFSNQE
     LWISLSASFF IKYFFYKGFV CVDGISLTIG SIKNNAFCVF LIPETILRTT IGQKIIGDVV
     NIEIDFYTQI TVDSVERLLK VHPSKFINCI DI