5,6-dimethylbenzimidazole synthase

5,6-dimethylbenzimidazole synthase (EC 1.14.99.40, BluB) is an enzyme with systematic name FMNH₂ oxidoreductase (5,6-dimethylbenzimidazole forming).^[1][2][3] This enzyme catalyses the following chemical reaction

FMNH₂ + NADH + H⁺ + O₂ ${\displaystyle \rightleftharpoons }$ 5,6-dimethylbenzimidazole + D-erythrose 4-phosphate + NAD⁺ + other product

5,6-dimethylbenzimidazole synthase
Identifiers
EC no.	1.14.99.40
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Search PMC articles PubMed articles NCBI proteins

The C-2 of 5,6-dimethylbenzimidazole is derived from C-1' of the ribityl group of FMNH₂ and 2-H from the ribityl 1'-pro-S hydrogen. This enzyme is part of the biosynthetic pathway to cobalamin (vitamin B₁₂) in bacteria.

See also

• Cobalamin biosynthesis