ID   BZAB_EUBLI              Reviewed;         427 AA.
AC   A0A0K1TQ05;
DT   27-SEP-2017, integrated into UniProtKB/Swiss-Prot.
DT   11-NOV-2015, sequence version 1.
DT   25-MAY-2022, entry version 26.
DE   RecName: Full=5-hydroxybenzimidazole synthase BzaB {ECO:0000305|PubMed:26246619};
DE            Short=5-OHBza synthase {ECO:0000305|PubMed:26246619};
DE            Short=HBI synthase;
DE            EC=4.1.99.23 {ECO:0000250|UniProtKB:P61425, ECO:0000305|PubMed:26246619};
GN   Name=bzaB {ECO:0000303|PubMed:26246619, ECO:0000312|EMBL:AKV89411.1};
GN   ORFNames=SAMN04515624_11453 {ECO:0000312|EMBL:SDP52021.1};
OS   Eubacterium limosum.
OC   Bacteria; Firmicutes; Clostridia; Eubacteriales; Eubacteriaceae;
OC   Eubacterium.
OX   NCBI_TaxID=1736;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA], FUNCTION, CATALYTIC ACTIVITY, AND
RP   PATHWAY.
RC   STRAIN=ATCC 10825 / DSM 20517 / JCM 9976 / NCIMB 9554 / NCTC 10469 / 32_A2;
RX   PubMed=26246619; DOI=10.1073/pnas.1509132112;
RA   Hazra A.B., Han A.W., Mehta A.P., Mok K.C., Osadchiy V., Begley T.P.,
RA   Taga M.E.;
RT   "Anaerobic biosynthesis of the lower ligand of vitamin B12.";
RL   Proc. Natl. Acad. Sci. U.S.A. 112:10792-10797(2015).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 10825 / DSM 20517 / JCM 9976 / NCIMB 9554 / NCTC 10469 / 32_A2;
RA   Varghese N.;
RL   Submitted (OCT-2016) to the EMBL/GenBank/DDBJ databases.
CC   -!- FUNCTION: Together with BzaA, catalyzes the conversion of
CC       aminoimidazole ribotide (AIR) to 5-hydroxybenzimidazole (5-HBI) in a
CC       radical S-adenosyl-L-methionine (SAM)-dependent reaction. Is thus
CC       involved in the anaerobic biosynthesis of dimethylbenzimidazole (DMB),
CC       the lower axial ligand of vitamin B12 (cobalamin). Requires BzaA for
CC       catalytic activity, as BzaB alone displays no activity.
CC       {ECO:0000269|PubMed:26246619}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=5-amino-1-(5-phospho-beta-D-ribosyl)imidazole + AH2 + S-
CC         adenosyl-L-methionine = 5'-deoxyadenosine + 5-hydroxybenzimidazole +
CC         A + formate + 2 H(+) + L-methionine + NH4(+) + phosphate;
CC         Xref=Rhea:RHEA:53504, ChEBI:CHEBI:13193, ChEBI:CHEBI:15378,
CC         ChEBI:CHEBI:15740, ChEBI:CHEBI:17319, ChEBI:CHEBI:17499,
CC         ChEBI:CHEBI:28938, ChEBI:CHEBI:43474, ChEBI:CHEBI:57844,
CC         ChEBI:CHEBI:59789, ChEBI:CHEBI:137404, ChEBI:CHEBI:137981;
CC         EC=4.1.99.23; Evidence={ECO:0000250|UniProtKB:P61425,
CC         ECO:0000305|PubMed:26246619};
CC   -!- COFACTOR:
CC       Name=[4Fe-4S] cluster; Xref=ChEBI:CHEBI:49883;
CC         Evidence={ECO:0000250|UniProtKB:P61425};
CC       Note=Binds 1 [4Fe-4S] cluster per subunit. The cluster is coordinated
CC       with 3 cysteines and an exchangeable S-adenosyl-L-methionine.
CC       {ECO:0000250|UniProtKB:Q9A6Q5};
CC   -!- PATHWAY: Cofactor biosynthesis; adenosylcobalamin biosynthesis.
CC       {ECO:0000305|PubMed:26246619}.
CC   -!- SIMILARITY: Belongs to the ThiC family. 5-hydroxybenzimidazole synthase
CC       subfamily. {ECO:0000305}.
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DR   EMBL; KT347435; AKV89411.1; -; Genomic_DNA.
DR   EMBL; FNJF01000014; SDP52021.1; -; Genomic_DNA.
DR   RefSeq; WP_074617800.1; NZ_FNJF01000014.1.
DR   AlphaFoldDB; A0A0K1TQ05; -.
DR   SMR; A0A0K1TQ05; -.
DR   STRING; 1736.ACH52_0363; -.
DR   EnsemblBacteria; SDP52021; SDP52021; SAMN04515624_11453.
DR   UniPathway; UPA00148; -.
DR   Proteomes; UP000182772; Unassembled WGS sequence.
DR   GO; GO:0051539; F:4 iron, 4 sulfur cluster binding; IEA:UniProtKB-KW.
DR   GO; GO:0016829; F:lyase activity; IEA:UniProtKB-KW.
DR   GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR   GO; GO:0009236; P:cobalamin biosynthetic process; IEA:UniProtKB-UniPathway.
DR   GO; GO:0009228; P:thiamine biosynthetic process; IEA:InterPro.
DR   Gene3D; 3.20.20.540; -; 1.
DR   InterPro; IPR038521; ThiC/Bza_core_dom.
DR   InterPro; IPR002817; ThiC/BzaA/B.
DR   PANTHER; PTHR30557; PTHR30557; 1.
DR   Pfam; PF01964; ThiC_Rad_SAM; 1.
DR   SFLD; SFLDF00407; phosphomethylpyrimidine_syntha; 1.
DR   TIGRFAMs; TIGR00190; thiC; 1.
PE   1: Evidence at protein level;
KW   4Fe-4S; Cobalamin biosynthesis; Iron; Iron-sulfur; Lyase; Metal-binding;
KW   S-adenosyl-L-methionine; Zinc.
FT   CHAIN           1..427
FT                   /note="5-hydroxybenzimidazole synthase BzaB"
FT                   /id="PRO_0000441746"
SQ   SEQUENCE   427 AA;  46040 MW;  5613BE2CE8D289F8 CRC64;
     MTQMLEARKG HITEEMEKVA LIEGVTPEFV REGVAKGHIV IPKNKFRSRD KICGIGGGLD
     VKVNGLMGTS SDRNDMEMEA KKLRILEECG ANAFMDLSTG DDIDAMRKQS LTISNIAAGC
     VPVYQASVEA IEKHGSMVGM TEDELFDTVE KQCQEGMDFM AIHSALNWSV LNALKKSGRV
     TDVVSRGGSF LTAWMFHNKK ENPLYEHFDR LLEILKATDT VLSIGDAIRP GANADSLDSA
     QVQGLIVAGE LTKRALEAGV QVMIEGPGHV PLNQIATTMQ LQKQLCYGVP YYILGFLATD
     VAPGYDNITG AIGGAFAGMH GADFLCYLTP AEHLGLPNED DVRMGVRTTK IAADAANVLK
     RGGNAWNRSL AMSKARVARD EKVQVANALD PEYLESKLKA EPESHGCAAC GKSKCPADVA
     AEFFGIA