Biosynthesis of vitamin B12: stereochemistry of transfer of a hydride equivalent from NADPH by precorrin-6x reductase
Abstract
Deuterium labelling with NMR analysis demonstrates that the enzyme precorrin-6x reductase transfers HR from C-4 of the pyridine residue of NADPH as the first step in the sequence leading from precorrin-6x to hydrogenobyrinic acid.