Protein
5,6-dimethylbenzimidazole synthase
Organism
Rhodobacter capsulatus (strain ATCC BAA-309 / NBRC 16581 / SB1003)
Function
Involved in the biosynthesis of cobalamin (vitamin B12). Catalyzes the oxidative fragmentation and contraction of the isoalloxazine heterocycle and the cleavage of the ribityl tail of FMNH(2) to form 5,6-dimethylbenzimidazole (DMB) and D-erythrose 4-phosphate (E4P). NAD(P)H is only required initially to reduce FMN and oxygen drives the oxidative fragmentation (By similarity).
Similarity
Belongs to the BluB family.
Sequence
MNFEQTHRDALTEVLRWRRDVRHFRPDPIDEAVIDRLRAVMDMAPSVGNARPWRVIRVDSPALRAEVLANFNAARAAAGSAYAGEQAEAYATLKLQGIDQAPLQLAVFTHRDPAAGHGLGRASMPVTLQQSTAMAIHTLWLAARAENLGLGMVSVLDPKAVERLLNAPPDWDFVAWLCIGVPEFTDDTPLLHRAGWQENLPTEWERR