Nicotinate-nucleotide-dimethylbenzimidazole phosphoribosyltransferase

In enzymology, a nicotinate-nucleotide-dimethylbenzimidazole phosphoribosyltransferase is an enzyme that catalyzes the chemical reaction


 * beta-nicotinate D-ribonucleotide + 5,6-dimethylbenzimidazole $$\rightleftharpoons$$ nicotinate + alpha-ribazole 5'-phosphate

Thus, the two substrates of this enzyme are beta-nicotinate D-ribonucleotide and 5,6-dimethylbenzimidazole, whereas its two products are nicotinate and alpha-ribazole 5'-phosphate.

This enzyme belongs to the family of glycosyltransferases, specifically the pentosyltransferases. The systematic name of this enzyme class is nicotinate-nucleotide:5,6-dimethylbenzimidazole phospho-D-ribosyltransferase. Other names in common use include CobT, nicotinate mononucleotide-dimethylbenzimidazole phosphoribosyltransferase, nicotinate ribonucleotide:benzimidazole (adenine) phosphoribosyltransferase, nicotinate-nucleotide:dimethylbenzimidazole phospho-D-ribosyltransferase, and nicotinate mononucleotide (NaMN):5,6-dimethylbenzimidazole phosphoribosyltransferase. This enzyme participates in the metabolism of riboflavin, porphyrin and chlorophyll.

Structural studies
As of late 2007, 28 structures have been solved for this class of enzymes, with PDB accession codes, , , , , , , , , , , , , , , , , , , , , , , , , , , and.