ID   RISB_NITEU              Reviewed;         164 AA.
AC   Q82S08;
DT   07-JUN-2004, integrated into UniProtKB/Swiss-Prot.
DT   01-JUN-2003, sequence version 1.
DT   03-AUG-2022, entry version 95.
DE   RecName: Full=6,7-dimethyl-8-ribityllumazine synthase {ECO:0000255|HAMAP-Rule:MF_00178};
DE            Short=DMRL synthase {ECO:0000255|HAMAP-Rule:MF_00178};
DE            Short=LS {ECO:0000255|HAMAP-Rule:MF_00178};
DE            Short=Lumazine synthase {ECO:0000255|HAMAP-Rule:MF_00178};
DE            EC=2.5.1.78 {ECO:0000255|HAMAP-Rule:MF_00178};
GN   Name=ribH {ECO:0000255|HAMAP-Rule:MF_00178}; OrderedLocusNames=NE2557;
OS   Nitrosomonas europaea (strain ATCC 19718 / CIP 103999 / KCTC 2705 / NBRC
OS   14298).
OC   Bacteria; Proteobacteria; Betaproteobacteria; Nitrosomonadales;
OC   Nitrosomonadaceae; Nitrosomonas.
OX   NCBI_TaxID=228410;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 19718 / CIP 103999 / KCTC 2705 / NBRC 14298;
RX   PubMed=12700255; DOI=10.1128/jb.185.9.2759-2773.2003;
RA   Chain P., Lamerdin J.E., Larimer F.W., Regala W., Lao V., Land M.L.,
RA   Hauser L., Hooper A.B., Klotz M.G., Norton J., Sayavedra-Soto L.A.,
RA   Arciero D.M., Hommes N.G., Whittaker M.M., Arp D.J.;
RT   "Complete genome sequence of the ammonia-oxidizing bacterium and obligate
RT   chemolithoautotroph Nitrosomonas europaea.";
RL   J. Bacteriol. 185:2759-2773(2003).
CC   -!- FUNCTION: Catalyzes the formation of 6,7-dimethyl-8-ribityllumazine by
CC       condensation of 5-amino-6-(D-ribitylamino)uracil with 3,4-dihydroxy-2-
CC       butanone 4-phosphate. This is the penultimate step in the biosynthesis
CC       of riboflavin. {ECO:0000255|HAMAP-Rule:MF_00178}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=(2S)-2-hydroxy-3-oxobutyl phosphate + 5-amino-6-(D-
CC         ribitylamino)uracil = 6,7-dimethyl-8-(1-D-ribityl)lumazine + H(+) + 2
CC         H2O + phosphate; Xref=Rhea:RHEA:26152, ChEBI:CHEBI:15377,
CC         ChEBI:CHEBI:15378, ChEBI:CHEBI:15934, ChEBI:CHEBI:43474,
CC         ChEBI:CHEBI:58201, ChEBI:CHEBI:58830; EC=2.5.1.78;
CC         Evidence={ECO:0000255|HAMAP-Rule:MF_00178};
CC   -!- PATHWAY: Cofactor biosynthesis; riboflavin biosynthesis; riboflavin
CC       from 2-hydroxy-3-oxobutyl phosphate and 5-amino-6-(D-
CC       ribitylamino)uracil: step 1/2. {ECO:0000255|HAMAP-Rule:MF_00178}.
CC   -!- SIMILARITY: Belongs to the DMRL synthase family. {ECO:0000255|HAMAP-
CC       Rule:MF_00178}.
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; AL954747; CAD86469.1; -; Genomic_DNA.
DR   RefSeq; WP_011113010.1; NC_004757.1.
DR   AlphaFoldDB; Q82S08; -.
DR   SMR; Q82S08; -.
DR   STRING; 228410.NE2557; -.
DR   EnsemblBacteria; CAD86469; CAD86469; NE2557.
DR   KEGG; neu:NE2557; -.
DR   eggNOG; COG0054; Bacteria.
DR   HOGENOM; CLU_089358_1_2_4; -.
DR   OMA; CQGVTQG; -.
DR   OrthoDB; 1680292at2; -.
DR   PhylomeDB; Q82S08; -.
DR   UniPathway; UPA00275; UER00404.
DR   Proteomes; UP000001416; Chromosome.
DR   GO; GO:0009349; C:riboflavin synthase complex; IEA:InterPro.
DR   GO; GO:0000906; F:6,7-dimethyl-8-ribityllumazine synthase activity; IEA:UniProtKB-UniRule.
DR   GO; GO:0009231; P:riboflavin biosynthetic process; IEA:UniProtKB-UniRule.
DR   CDD; cd09209; Lumazine_synthase-I; 1.
DR   Gene3D; 3.40.50.960; -; 1.
DR   HAMAP; MF_00178; Lumazine_synth; 1.
DR   InterPro; IPR034964; LS.
DR   InterPro; IPR002180; LS/RS.
DR   InterPro; IPR036467; LS/RS_sf.
DR   PANTHER; PTHR21058; PTHR21058; 1.
DR   Pfam; PF00885; DMRL_synthase; 1.
DR   SUPFAM; SSF52121; SSF52121; 1.
DR   TIGRFAMs; TIGR00114; lumazine-synth; 1.
PE   3: Inferred from homology;
KW   Reference proteome; Riboflavin biosynthesis; Transferase.
FT   CHAIN           1..164
FT                   /note="6,7-dimethyl-8-ribityllumazine synthase"
FT                   /id="PRO_0000134776"
FT   ACT_SITE        94
FT                   /note="Proton donor"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00178"
FT   BINDING         28
FT                   /ligand="5-amino-6-(D-ribitylamino)uracil"
FT                   /ligand_id="ChEBI:CHEBI:15934"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00178"
FT   BINDING         62..64
FT                   /ligand="5-amino-6-(D-ribitylamino)uracil"
FT                   /ligand_id="ChEBI:CHEBI:15934"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00178"
FT   BINDING         86..88
FT                   /ligand="5-amino-6-(D-ribitylamino)uracil"
FT                   /ligand_id="ChEBI:CHEBI:15934"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00178"
FT   BINDING         91..92
FT                   /ligand="(2S)-2-hydroxy-3-oxobutyl phosphate"
FT                   /ligand_id="ChEBI:CHEBI:58830"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00178"
FT   BINDING         119
FT                   /ligand="5-amino-6-(D-ribitylamino)uracil"
FT                   /ligand_id="ChEBI:CHEBI:15934"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00178"
FT   BINDING         133
FT                   /ligand="(2S)-2-hydroxy-3-oxobutyl phosphate"
FT                   /ligand_id="ChEBI:CHEBI:58830"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00178"
SQ   SEQUENCE   164 AA;  17460 MW;  89EFD501FECB4735 CRC64;
     MSYYDNILEI DSNLDGNGLC IGIVMSRFNI DVSEGLLGAC TAELTRLGVQ EADIVLTTVP
     GALEIPVALQ KLAESDRFDA LIALGAVIRG ETYHFEVVAN ESARGLAAVG REYNIPIANG
     ILTTDDEDQA TARMAEKGGE TARVAIEMAN LVLTLDEMDQ SAPT