ID   RISB_METMJ              Reviewed;         135 AA.
AC   A3CRJ3;
DT   15-JAN-2008, integrated into UniProtKB/Swiss-Prot.
DT   20-MAR-2007, sequence version 1.
DT   03-AUG-2022, entry version 80.
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=Memar_0058;
OS   Methanoculleus marisnigri (strain ATCC 35101 / DSM 1498 / JR1).
OC   Archaea; Euryarchaeota; Stenosarchaea group; Methanomicrobia;
OC   Methanomicrobiales; Methanomicrobiaceae; Methanoculleus.
OX   NCBI_TaxID=368407;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 35101 / DSM 1498 / JR1;
RX   PubMed=21304656; DOI=10.4056/sigs.32535;
RA   Anderson I.J., Sieprawska-Lupa M., Lapidus A., Nolan M., Copeland A.,
RA   Glavina Del Rio T., Tice H., Dalin E., Barry K., Saunders E., Han C.,
RA   Brettin T., Detter J.C., Bruce D., Mikhailova N., Pitluck S., Hauser L.,
RA   Land M., Lucas S., Richardson P., Whitman W.B., Kyrpides N.C.;
RT   "Complete genome sequence of Methanoculleus marisnigri Romesser et al. 1981
RT   type strain JR1.";
RL   Stand. Genomic Sci. 1:189-196(2009).
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; CP000562; ABN55993.1; -; Genomic_DNA.
DR   RefSeq; WP_011842914.1; NC_009051.1.
DR   AlphaFoldDB; A3CRJ3; -.
DR   SMR; A3CRJ3; -.
DR   STRING; 368407.Memar_0058; -.
DR   EnsemblBacteria; ABN55993; ABN55993; Memar_0058.
DR   GeneID; 4846286; -.
DR   KEGG; mem:Memar_0058; -.
DR   eggNOG; arCOG01323; Archaea.
DR   HOGENOM; CLU_089358_3_1_2; -.
DR   OMA; SGPGMTR; -.
DR   OrthoDB; 88531at2157; -.
DR   UniPathway; UPA00275; UER00404.
DR   Proteomes; UP000002146; 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   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..135
FT                   /note="6,7-dimethyl-8-ribityllumazine synthase"
FT                   /id="PRO_1000040450"
FT   ACT_SITE        76
FT                   /note="Proton donor"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00178"
FT   BINDING         12
FT                   /ligand="5-amino-6-(D-ribitylamino)uracil"
FT                   /ligand_id="ChEBI:CHEBI:15934"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00178"
FT   BINDING         44..46
FT                   /ligand="5-amino-6-(D-ribitylamino)uracil"
FT                   /ligand_id="ChEBI:CHEBI:15934"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00178"
FT   BINDING         68..70
FT                   /ligand="5-amino-6-(D-ribitylamino)uracil"
FT                   /ligand_id="ChEBI:CHEBI:15934"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00178"
FT   BINDING         73..74
FT                   /ligand="(2S)-2-hydroxy-3-oxobutyl phosphate"
FT                   /ligand_id="ChEBI:CHEBI:58830"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00178"
FT   BINDING         101
FT                   /ligand="5-amino-6-(D-ribitylamino)uracil"
FT                   /ligand_id="ChEBI:CHEBI:15934"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00178"
FT   BINDING         116
FT                   /ligand="(2S)-2-hydroxy-3-oxobutyl phosphate"
FT                   /ligand_id="ChEBI:CHEBI:58830"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00178"
SQ   SEQUENCE   135 AA;  14895 MW;  A3D4688C5770F016 CRC64;
     MTVKLGFVVA EFNRDITYMM EIEAREHAGF LDAEVADTIY VPGAYDMPLA IKKLLERGEI
     DAVVTIGCVI EGATQHDEIV VQHAARKIID LSLEFGKPVA LGISGPGMTR MEATERIDYA
     KRAVESAVKM VQRLE