KEGG   ENZYME: 4.1.99.23
Entry
EC 4.1.99.23                Enzyme                                 
Name
5-hydroxybenzimidazole synthase;
bzaF (gene name);
HBI synthase
Class
Lyases;
Carbon-carbon lyases;
Other carbon-carbon lyases
Sysname
5-amino-1-(5-phospho-beta-D-ribosyl)imidazole formate-lyase (5-hydroxybenzimidazole-forming)
Reaction(IUBMB)
5-amino-1-(5-phospho-beta-D-ribosyl)imidazole + S-adenosyl-L-methionine + reduced acceptor = 5-hydroxybenzimidazole + 5'-deoxyadenosine + L-methionine + formate + NH3 + phosphate + oxidized acceptor [RN:R11919]
Reaction(KEGG)
R11919
Substrate
5-amino-1-(5-phospho-beta-D-ribosyl)imidazole [CPD:C03373];
S-adenosyl-L-methionine [CPD:C00019];
reduced acceptor [CPD:C00030]
Product
5-hydroxybenzimidazole [CPD:C21764];
5'-deoxyadenosine [CPD:C05198];
L-methionine [CPD:C00073];
formate [CPD:C00058];
NH3 [CPD:C00014];
phosphate [CPD:C00009];
oxidized acceptor
Comment
The enzyme, purified from bacteria, is part of the anaerobic pathway for cobalamin biosynthesis. It binds a [4Fe-4S] cluster that is coordinated by 3 cysteines and an exchangeable S-adenosyl-L-methionine molecule. The first stage of catalysis is reduction of the S-adenosyl-L-methionine to produce L-methionine and a 5'-deoxyadenosin-5'-yl radical that is crucial for the conversion of the substrate.
History
EC 4.1.99.23 created 2017
Pathway
ec00860  Porphyrin metabolism
ec01100  Metabolic pathways
Orthology
K22465  5-hydroxybenzimidazole synthase
K22466  5-hydroxybenzimidazole synthase
Genes
GSUGSU3005(thiC-2)
GSKKN400_2948(thiC-2)
GMEGmet_0471(thiC-2)
GPIGPICK_02630
GAOA2G06_14140
GBZJZM60_08015(thiC)
GEMGM21_3893
GEBGM18_4239
GEFFO488_14370(thiC)
GURGura_4183
GEOGeob_0543(thiC-2)
GLOGlov_3677
TAMMGEAMG1_2108(bzaF)
GBMGbem_3809(thiC-2)
GBNGEOBRER4_37000(thiC)
GERKP004_18205(thiC)
GSUBKP001_18030(thiC)
GNTKP003_18225(thiC)
GPLM1B72_01565(thiC)
PPDPpro_2809
DEUDBW_3101
DVEDESUT3_08050(thiC)
DEPAOP6_0798(thiC)
DESDSOUD_0618(thiC-2)
DSFUWK_02784
DAKDaAHT2_1596
DBKDGMP_09610(thiC_1)
DDUGF1_11200(thiC)
DALDalk_0439
DATHRM2_06760(thiC)
DTOTOL2_C39750(thiC2)
DWDDSCW_64740(thiC)
DALKDSCA_61910(thiC_2)
DMLDmul_38190(thiC2)
DLIdnl_04700(thiC2)
DEKDSLASN_49290(thiC_2)
DBRDeba_2032
TAVG4V39_09730(thiC)
TMAIFVE67_00935(thiC)
DHRLGS26_04000(thiC)
CACECACET_c19200(thiC1) CACET_c19210(thiC2)
CFMBJL90_15685 BJL90_15690
DORDesor_2648 Desor_2649
DAIDesaci_2510 Desaci_2511
DMIDesmer_3480 Desmer_3481
DAEDtox_1596 Dtox_1597
DKUDesku_0278 Desku_0279
AACXDEACI_0774 DEACI_0775
TJRTherJR_0550 TherJR_0551
DGIDesgi_1093 Desgi_1094
ELMELI_4215 ELI_4216
EMTCPZ25_011275 CPZ25_011280
ELIMB2M23_05585 B2M23_05590
AWOAwo_c14630(thiC2) Awo_c14640(thiC3)
AWICHL1_002404(thiC) CHL1_002405(bzaB)
TPZTph_c22270(thiC2) Tph_c22280(thiC3)
MTAMoth_1722 Moth_1723
MTHOMOTHE_c17310(thiC2) MOTHE_c17320(thiC3)
MTHZMOTHA_c18140(thiC2) MOTHA_c18150(thiC3)
CALKHUE98_02155(thiC) HUE98_02160(bzaB)
DFODform_00448(thiC) Dform_00449
BROCIPI25_07410(thiC)
BPITBPIT_18350
DTPJZK55_23310(thiC_2)
 » show all
Reference
1  [PMID:26237670]
  Authors
Mehta AP, Abdelwahed SH, Fenwick MK, Hazra AB, Taga ME, Zhang Y, Ealick SE, Begley TP
  Title
Anaerobic 5-Hydroxybenzimidazole Formation from Aminoimidazole Ribotide: An Unanticipated Intersection of Thiamin and Vitamin B(1)(2) Biosynthesis.
  Journal
J Am Chem Soc 137:10444-7 (2015)
DOI:10.1021/jacs.5b03576
Reference
2  [PMID:26246619]
  Authors
Hazra AB, Han AW, Mehta AP, Mok KC, Osadchiy V, Begley TP, Taga ME
  Title
Anaerobic biosynthesis of the lower ligand of vitamin B12.
  Journal
Proc Natl Acad Sci U S A 112:10792-7 (2015)
DOI:10.1073/pnas.1509132112
  Sequence
Other DBs
ExplorEnz - The Enzyme Database: 4.1.99.23
IUBMB Enzyme Nomenclature: 4.1.99.23
ExPASy - ENZYME nomenclature database: 4.1.99.23
BRENDA, the Enzyme Database: 4.1.99.23

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