ID   RISB_MYCSK              Reviewed;         160 AA.
AC   A1UFM8;
DT   15-JAN-2008, integrated into UniProtKB/Swiss-Prot.
DT   06-FEB-2007, sequence version 1.
DT   05-FEB-2025, entry version 96.
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};
GN   OrderedLocusNames=Mkms_2438;
OS   Mycobacterium sp. (strain KMS).
OC   Bacteria; Bacillati; Actinomycetota; Actinomycetes; Mycobacteriales;
OC   Mycobacteriaceae; Mycobacterium.
OX   NCBI_TaxID=189918;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=KMS;
RG   US DOE Joint Genome Institute;
RA   Copeland A., Lucas S., Lapidus A., Barry K., Detter J.C.,
RA   Glavina del Rio T., Hammon N., Israni S., Dalin E., Tice H., Pitluck S.,
RA   Kiss H., Brettin T., Bruce D., Han C., Tapia R., Gilna P., Schmutz J.,
RA   Larimer F., Land M., Hauser L., Kyrpides N., Mikhailova N., Miller C.D.,
RA   Richardson P.;
RT   "Complete sequence of chromosome of Mycobacterium sp. KMS.";
RL   Submitted (DEC-2006) 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 +
CC         phosphate + 2 H2O + H(+); 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   -!- SUBUNIT: Homopentamer. {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; CP000518; ABL91636.1; -; Genomic_DNA.
DR   AlphaFoldDB; A1UFM8; -.
DR   SMR; A1UFM8; -.
DR   STRING; 189918.Mkms_2438; -.
DR   KEGG; mkm:Mkms_2438; -.
DR   HOGENOM; CLU_089358_1_2_11; -.
DR   OrthoDB; 9809709at2; -.
DR   UniPathway; UPA00275; UER00404.
DR   GO; GO:0005829; C:cytosol; IEA:TreeGrafter.
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; Lumazine/riboflavin synthase; 1.
DR   HAMAP; MF_00178; Lumazine_synth; 1.
DR   InterPro; IPR034964; LS.
DR   InterPro; IPR002180; LS/RS.
DR   InterPro; IPR036467; LS/RS_sf.
DR   NCBIfam; TIGR00114; lumazine-synth; 1.
DR   PANTHER; PTHR21058:SF0; 6,7-DIMETHYL-8-RIBITYLLUMAZINE SYNTHASE; 1.
DR   PANTHER; PTHR21058; 6,7-DIMETHYL-8-RIBITYLLUMAZINE SYNTHASE DMRL SYNTHASE LUMAZINE SYNTHASE; 1.
DR   Pfam; PF00885; DMRL_synthase; 1.
DR   SUPFAM; SSF52121; Lumazine synthase; 1.
PE   3: Inferred from homology;
KW   Riboflavin biosynthesis; Transferase.
FT   CHAIN           1..160
FT                   /note="6,7-dimethyl-8-ribityllumazine synthase"
FT                   /id="PRO_1000040456"
FT   ACT_SITE        89
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         59..61
FT                   /ligand="5-amino-6-(D-ribitylamino)uracil"
FT                   /ligand_id="ChEBI:CHEBI:15934"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00178"
FT   BINDING         81..83
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..87
FT                   /ligand="(2S)-2-hydroxy-3-oxobutyl phosphate"
FT                   /ligand_id="ChEBI:CHEBI:58830"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00178"
FT   BINDING         114
FT                   /ligand="5-amino-6-(D-ribitylamino)uracil"
FT                   /ligand_id="ChEBI:CHEBI:15934"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00178"
FT   BINDING         128
FT                   /ligand="(2S)-2-hydroxy-3-oxobutyl phosphate"
FT                   /ligand_id="ChEBI:CHEBI:58830"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00178"
SQ   SEQUENCE   160 AA;  16110 MW;  9E1B9A2F4015006A CRC64;
     MSGGAGVPDL PQIDASGMKV GIVASTWHST ICDALLDGAL KVTESANVSE PTVVRVLGAI
     EIPVVAQALA ADHEAVIALG VVIRGQTPHF DYVCDAVTQG LTRVSLDAST PVANGVLTTN
     TEEQALDRAG LPGSAEDKGA QAAAAALSTA LTLQGLRGRS
//