Converts cobyric acid to cobinamide by the addition of aminopropanol on the F carboxylic group. Cofactor biosynthesis; adenosylcobalamin biosynthesis. Belongs to the CobD/CbiB family. Was originally thought to originate from Pseudomonas denitrificans, but similarity searches show that the sequence is much closer to Sinorhizobium. The entry's taxonomy has been changed.