The enzyme is involved in the biosynthesis of phenolic cobamides in the Gram-positive bacterium Sporomusa ovata. It can also transfer the phospho-D-ribosyl group to 4-methylphenol and 5,6-dimethylbenzimidazole. The related EC 2.4.2.21, nicotinate-nucleotide dimethylbenzimidazole phosphoribosyltransferase, also transfers the phospho-D-ribosyl group from nicotinate D-ribonucleotide to 5,6-dimethylbenzimidazole, but shows no activity with 4-methylphenol or phenol.