EC - Nicotinate-nucleotide—dimethylbenzimidazole phosphoribosyltransferase

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IntEnz Enzyme Nomenclature


Accepted name:
nicotinate-nucleotide—dimethylbenzimidazole phosphoribosyltransferase
Other names:
nicotinate mononucleotide-dimethylbenzimidazole phosphoribosyltransferase
nicotinate ribonucleotide:benzimidazole (adenine) phosphoribosyltransferase
nicotinate-nucleotide:dimethylbenzimidazole phospho-D-ribosyltransferase
nicotinate mononucleotide (NaMN):5,6-dimethylbenzimidazole phosphoribosyltransferase
Systematic name:
nicotinate-nucleotide:5,6-dimethylbenzimidazole phospho-D-ribosyltransferase



Also acts on benzimidazole, and the clostridial enzyme acts on adenine to form 7-α-D-ribosyladenine 5'-phosphate. The product of the reaction, α-ribazole 5'-phosphate, forms part of the corrin-biosynthesis pathway and is a substrate for EC, adenosylcobinamide-GDP ribazoletransferase [4]. It can also be dephosphorylated to form α-ribazole by the action of EC, α-ribazole phosphatase.

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , DIAGRAM , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , UniPathway
Structural data: CSA , EC2PDB
Gene Ontology: GO:0008939
CAS Registry Number: 37277-76-2
UniProtKB/Swiss-Prot: (205) [show] [UniProt]


  1. Friedmann, H.C.
    Partial purification and properties of a single displacement trans-N-glycosidase.
    J. Biol. Chem. 240 : 413-418 (1965). [PMID: 14253445]
  2. Friedmann, H.C. and Fyfe, J.A.
    Pseudovitamin B12 biosynthesis. Enzymatic formation of a new adenylic acid, 7-α-D-ribofuranosyladenine 5'-phosphate.
    J. Biol. Chem. 244 : 1667-1671 (1969). [PMID: 5780835]
  3. Fyfe, J.A. and Friedmann, H.C.
    Vitamin B12 biosynthesis. Enzyme studies on the formation of the α-glycosidic nucleotide precursor.
    J. Biol. Chem. 244 : 1659-1666 (1969). [PMID: 4238408]
  4. Cameron, B., Blanche, F., Rouyez, M.-C., Bisch, D., Famechon, A., Couder, M., Cauchois, L., Thibaut, D., Debussche, L. and Crouzet, J.
    Genetic analysis, nucleotide sequence, and products of two Pseudomonas denitrificans cob genes encoding nicotinate-nucleotide: dimethylbenzimidazole phosphoribosyltransferase and cobalamin (5'-phosphate) synthase.
    J. Bacteriol. 173 : 6066-6073 (1991). [PMID: 1917841]
  5. Cheong, C.-G., Escalante-Semerena, J.C. and Rayment, I.
    Structural investigation of the biosynthesis of alternative lower ligands for cobamides by nicotinate mononucleotide: 5,6-dimethylbenzimidazole phosphoribosyltransferase from Salmonella enterica.
    J. Biol. Chem. 276 : 37612-37620 (2001). [PMID: 11441022]
  6. Cheong, C.-G., Escalante-Semerena, J.C. and Rayment, I.
    Capture of a labile substrate by expulsion of water molecules from the active site of nicotinate mononucleotide:5,6-dimethylbenzimidazole phosphoribosyltransferase (CobT) from Salmonella enterica.
    J. Biol. Chem. 277 : 41120-41127 (2002). [PMID: 12101181]

[EC created 1972]