ID   RIBB_CHLL2              Reviewed;         222 AA.
AC   B3EEP4;
DT   24-MAR-2009, integrated into UniProtKB/Swiss-Prot.
DT   22-JUL-2008, sequence version 1.
DT   02-SEP-2026, entry version 86.
DE   RecName: Full=3,4-dihydroxy-2-butanone 4-phosphate synthase {ECO:0000255|HAMAP-Rule:MF_00180};
DE            Short=DHBP synthase {ECO:0000255|HAMAP-Rule:MF_00180};
DE            EC=4.1.99.12 {ECO:0000255|HAMAP-Rule:MF_00180};
GN   Name=ribB {ECO:0000255|HAMAP-Rule:MF_00180};
GN   OrderedLocusNames=Clim_0178;
OS   Chlorobium limicola (strain DSM 245 / NBRC 103803 / 6330).
OC   Bacteria; Pseudomonadati; Chlorobiota; Chlorobiia; Chlorobiales;
OC   Chlorobiaceae; Chlorobium/Pelodictyon group; Chlorobium.
OX   NCBI_TaxID=290315;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=DSM 245 / NBRC 103803 / 6330;
RG   US DOE Joint Genome Institute;
RA   Lucas S., Copeland A., Lapidus A., Glavina del Rio T., Dalin E., Tice H.,
RA   Bruce D., Goodwin L., Pitluck S., Schmutz J., Larimer F., Land M.,
RA   Hauser L., Kyrpides N., Ovchinnikova G., Zhao F., Li T., Liu Z.,
RA   Overmann J., Bryant D.A., Richardson P.;
RT   "Complete sequence of Chlorobium limicola DSM 245.";
RL   Submitted (MAY-2008) to the EMBL/GenBank/DDBJ databases.
CC   -!- FUNCTION: Catalyzes the conversion of D-ribulose 5-phosphate to formate
CC       and 3,4-dihydroxy-2-butanone 4-phosphate. {ECO:0000255|HAMAP-
CC       Rule:MF_00180}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=D-ribulose 5-phosphate = (2S)-2-hydroxy-3-oxobutyl phosphate +
CC         formate + H(+); Xref=Rhea:RHEA:18457, ChEBI:CHEBI:15378,
CC         ChEBI:CHEBI:15740, ChEBI:CHEBI:58121, ChEBI:CHEBI:58830;
CC         EC=4.1.99.12; Evidence={ECO:0000255|HAMAP-Rule:MF_00180};
CC   -!- COFACTOR:
CC       Name=Mg(2+); Xref=ChEBI:CHEBI:18420; Evidence={ECO:0000255|HAMAP-
CC         Rule:MF_00180};
CC       Name=Mn(2+); Xref=ChEBI:CHEBI:29035; Evidence={ECO:0000255|HAMAP-
CC         Rule:MF_00180};
CC       Note=Binds 2 divalent metal cations per subunit. Magnesium or
CC       manganese. {ECO:0000255|HAMAP-Rule:MF_00180};
CC   -!- PATHWAY: Cofactor biosynthesis; riboflavin biosynthesis; 2-hydroxy-3-
CC       oxobutyl phosphate from D-ribulose 5-phosphate: step 1/1.
CC       {ECO:0000255|HAMAP-Rule:MF_00180}.
CC   -!- SUBUNIT: Homodimer. {ECO:0000255|HAMAP-Rule:MF_00180}.
CC   -!- SIMILARITY: Belongs to the DHBP synthase family. {ECO:0000255|HAMAP-
CC       Rule:MF_00180}.
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DR   EMBL; CP001097; ACD89277.1; -; Genomic_DNA.
DR   RefSeq; WP_012465158.1; NC_010803.1.
DR   AlphaFoldDB; B3EEP4; -.
DR   SMR; B3EEP4; -.
DR   STRING; 290315.Clim_0178; -.
DR   KEGG; cli:Clim_0178; -.
DR   eggNOG; COG0108; Bacteria.
DR   HOGENOM; CLU_020273_3_0_10; -.
DR   OrthoDB; 9793111at2; -.
DR   UniPathway; UPA00275; UER00399.
DR   GO; GO:0005829; C:cytosol; IEA:TreeGrafter.
DR   GO; GO:0008686; F:3,4-dihydroxy-2-butanone-4-phosphate synthase activity; IEA:UniProtKB-UniRule.
DR   GO; GO:0000287; F:magnesium ion binding; IEA:UniProtKB-UniRule.
DR   GO; GO:0030145; F:manganese ion binding; IEA:UniProtKB-UniRule.
DR   GO; GO:0009231; P:riboflavin biosynthetic process; IEA:UniProtKB-UniRule.
DR   FunFam; 3.90.870.10:FF:000002; 3,4-dihydroxy-2-butanone 4-phosphate synthase; 1.
DR   Gene3D; 3.90.870.10; DHBP synthase; 1.
DR   HAMAP; MF_00180; RibB; 1.
DR   InterPro; IPR017945; DHBP_synth_RibB-like_a/b_dom.
DR   InterPro; IPR000422; DHBP_synthase_RibB.
DR   NCBIfam; TIGR00506; ribB; 1.
DR   PANTHER; PTHR21327:SF38; 3,4-DIHYDROXY-2-BUTANONE 4-PHOSPHATE SYNTHASE; 1.
DR   PANTHER; PTHR21327; GTP CYCLOHYDROLASE II-RELATED; 1.
DR   Pfam; PF00926; DHBP_synthase; 1.
DR   SUPFAM; SSF55821; YrdC/RibB; 1.
PE   3: Inferred from homology;
KW   Lyase; Magnesium; Manganese; Metal-binding; Riboflavin biosynthesis.
FT   CHAIN           1..222
FT                   /note="3,4-dihydroxy-2-butanone 4-phosphate synthase"
FT                   /id="PRO_1000098275"
FT   BINDING         37..38
FT                   /ligand="D-ribulose 5-phosphate"
FT                   /ligand_id="ChEBI:CHEBI:58121"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00180"
FT   BINDING         38
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_label="1"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00180"
FT   BINDING         38
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_label="2"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00180"
FT   BINDING         42
FT                   /ligand="D-ribulose 5-phosphate"
FT                   /ligand_id="ChEBI:CHEBI:58121"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00180"
FT   BINDING         150..154
FT                   /ligand="D-ribulose 5-phosphate"
FT                   /ligand_id="ChEBI:CHEBI:58121"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00180"
FT   BINDING         153
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_label="2"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00180"
FT   BINDING         174
FT                   /ligand="D-ribulose 5-phosphate"
FT                   /ligand_id="ChEBI:CHEBI:58121"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00180"
FT   SITE            136
FT                   /note="Essential for catalytic activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00180"
FT   SITE            174
FT                   /note="Essential for catalytic activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00180"
SQ   SEQUENCE   222 AA;  23594 MW;  15E6D1814CC28655 CRC64;
     MNQMLPEQLL NQLNLVEKAL AALRNGQGVL VADDPGRENE ADLIFPAESV TIPQMALLIR
     ECSGIVCLCM TDGKIRSLEL PMMVENNTSG FQTAFTVSIE AAEGVTTGVS AADRVKTVRT
     AVSENARPSD LRHPGHIFPL RARPGGVLER PGHTEATVDL MRLAGLSPAG VLCELTNPDG
     SMAGIEETFA FSVQHGFPVL SIGDIVAYRK SLLQTGSQGL SA
//