Entry
Name
5-hydroxybenzimidazole synthase;
bzaF (gene name);
HBI synthase
Class
Lyases;
Carbon-carbon lyases;
Other carbon-carbon lyases
BRITE hierarchy
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)
Substrate
5-amino-1-(5-phospho-beta-D-ribosyl)imidazole [CPD:
C03373 ];
S-adenosyl-L-methionine [CPD:
C00019 ];
reduced acceptor [CPD:
C00030 ]
Product
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
Orthology
K22465 5-hydroxybenzimidazole synthase
K22466 5-hydroxybenzimidazole synthase
Genes
GEC : GEO60473_24280(thiC_2)
GBN : GEOBRER4_37000(thiC)
DEK : DSLASN_49290(thiC_2)
CACE : CACET_c19200(thiC1) CACET_c19210(thiC2)
CFM : BJL90_15685 BJL90_15690
DOR : Desor_2648 Desor_2649
DAI : Desaci_2510 Desaci_2511
DMI : Desmer_3480 Desmer_3481
DKU : Desku_0278 Desku_0279
AACX : DEACI_0774 DEACI_0775
TJR : TherJR_0550 TherJR_0551
DGI : Desgi_1093 Desgi_1094
EMT : CPZ25_011275 CPZ25_011280
ELIM : B2M23_05585 B2M23_05590
AWO : Awo_c14630(thiC2) Awo_c14640(thiC3)
AWI : CHL1_002404(thiC) CHL1_002405(bzaB)
TPZ : Tph_c22270(thiC2) Tph_c22280(thiC3)
MTHO : MOTHE_c17310(thiC2) MOTHE_c17320(thiC3)
MTHZ : MOTHA_c18140(thiC2) MOTHA_c18150(thiC3)
CALK : HUE98_02155(thiC) HUE98_02160(bzaB)
DFO : Dform_00448(thiC) Dform_00449
» show all
Taxonomy
Reference
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
Reference
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
Sequence
Other DBs
ExPASy - ENZYME nomenclature database: 4.1.99.23