Construction of a third NAD+de novobiosynthesis pathway

Abstract

AbstractOnly twode novobiosynthetic routes to nicotinamide adenine dinucleotide (NAD+) have been described, both of which start from a proteinogenic amino acid and are tightly controlled. Here we establish a C3N pathway starting from chorismate inEscherichia colias a third NAD+de novobiosynthesis pathway. Significantly, the C3N pathway yielded extremely high cellular concentrations of NAD(H) inE. coli. Its utility in cofactor engineering was demonstrated by introducing the four-gene C3N module to cell factories to achieve higher production of 2,5-dimethylpyrazine and develop an efficient C3N-based whole-cell bioconversion system for preparing chiral amines. The wide distribution and abundance of chorismate in most kingdoms of life implies a general utility of the C3N pathway for modulating cellular levels of NAD(H) in versatile organisms.