Escherichia coli Strain Designed for Characterizing in Vivo Functions of Nicotinamide Adenine Dinucleotide Analogues.

An Escherichia coli strain was constructed for the efficient import of nicotinamide adenine dinucleotide (NAD) analogues into cells by limiting extracellular degradation while expressing an efficient NAD importer. In vivo functions of three NAD analogues were characterized. Nicotinamide hypoxanthine dinucleotide was identified as an inhibitor of NAD synthesis. Nicotinamide cytosine dinucleotide had excellent biocompatibility and was used for characterizing a growth-dependent degradation of in vivo nicotinamide cofactors.