Abstract
The redox cofactor β-nicotinamide adenine dinucleotide (NAD) has been revealed to serve as a building block for the biosynthesis of an alkaloid natural product, altemicidin. The biosynthetic pathway investigation identified a unique pyridoxal pyrophosphate (PLP)-dependent enzyme that utilizes NAD and S-adenosylmethionine (SAM) to build the bicyclic alkaloid scaffold, opening the door for biosynthetic studies of NAD-derived natural products.