ID   RISB_METS4              Reviewed;         181 AA.
AC   B0UHS5;
DT   28-JUL-2009, integrated into UniProtKB/Swiss-Prot.
DT   08-APR-2008, sequence version 1.
DT   03-AUG-2022, entry version 79.
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=M446_6800;
OS   Methylobacterium sp. (strain 4-46).
OC   Bacteria; Proteobacteria; Alphaproteobacteria; Hyphomicrobiales;
OC   Methylobacteriaceae; Methylobacterium.
OX   NCBI_TaxID=426117;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=4-46;
RG   US DOE Joint Genome Institute;
RA   Copeland A., Lucas S., Lapidus A., Glavina del Rio T., Dalin E., Tice H.,
RA   Bruce D., Goodwin L., Pitluck S., Chertkov O., Brettin T., Detter J.C.,
RA   Han C., Kuske C.R., Schmutz J., Larimer F., Land M., Hauser L.,
RA   Kyrpides N., Ivanova N., Marx C.J., Richardson P.;
RT   "Complete sequence of chromosome of Methylobacterium sp. 4-46.";
RL   Submitted (FEB-2008) to the EMBL/GenBank/DDBJ databases.
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}.
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DR   EMBL; CP000943; ACA21045.1; -; Genomic_DNA.
DR   RefSeq; WP_012336419.1; NC_010511.1.
DR   AlphaFoldDB; B0UHS5; -.
DR   SMR; B0UHS5; -.
DR   STRING; 426117.M446_6800; -.
DR   PRIDE; B0UHS5; -.
DR   EnsemblBacteria; ACA21045; ACA21045; M446_6800.
DR   KEGG; met:M446_6800; -.
DR   eggNOG; COG0054; Bacteria.
DR   HOGENOM; CLU_089358_1_2_5; -.
DR   OMA; CQGVTQG; -.
DR   OrthoDB; 1680292at2; -.
DR   UniPathway; UPA00275; UER00404.
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   Riboflavin biosynthesis; Transferase.
FT   CHAIN           1..181
FT                   /note="6,7-dimethyl-8-ribityllumazine synthase"
FT                   /id="PRO_1000195501"
FT   ACT_SITE        95
FT                   /note="Proton donor"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00178"
FT   BINDING         27
FT                   /ligand="5-amino-6-(D-ribitylamino)uracil"
FT                   /ligand_id="ChEBI:CHEBI:15934"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00178"
FT   BINDING         58..60
FT                   /ligand="5-amino-6-(D-ribitylamino)uracil"
FT                   /ligand_id="ChEBI:CHEBI:15934"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00178"
FT   BINDING         87..89
FT                   /ligand="5-amino-6-(D-ribitylamino)uracil"
FT                   /ligand_id="ChEBI:CHEBI:15934"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00178"
FT   BINDING         92..93
FT                   /ligand="(2S)-2-hydroxy-3-oxobutyl phosphate"
FT                   /ligand_id="ChEBI:CHEBI:58830"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00178"
FT   BINDING         120
FT                   /ligand="5-amino-6-(D-ribitylamino)uracil"
FT                   /ligand_id="ChEBI:CHEBI:15934"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00178"
FT   BINDING         134
FT                   /ligand="(2S)-2-hydroxy-3-oxobutyl phosphate"
FT                   /ligand_id="ChEBI:CHEBI:58830"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00178"
SQ   SEQUENCE   181 AA;  19127 MW;  82AFD8D4A18A1FFF CRC64;
     MVTPRRDSGK DRPSLKDARI LVVEARYYED IADELLRGAT AAIAAAQAEA EVVTVPGALE
     IPQAVAILVE AAAREARPYD AVVALGCVIR GETGHYDIVA GESARALMDL SVLLRLPLGN
     GILTVETEAQ AQARARVSEM NKGGGAAEAA LAVLALKRAK AAERPDRTIG FTPRRTAETQ
     E