NAD synthase (glutamine hydrolysing)

In enzymology, a NAD+ synthase (glutamine-hydrolysing) (EC 6.3.5.1) is an enzyme that catalyzes the chemical reaction

ATP + deamido-NAD⁺ + L-glutamine + H₂O ⇌ AMP + diphosphate + NAD⁺ + L-glutamate. In eukaryotes, this enzyme contains a glutaminase domain related to nitrilase.

The substrates of this enzyme are ATP, deamido-NAD+, L-glutamine, and H₂O, whereas its 4 products are AMP, diphosphate, NAD⁺, and glutamate

This enzyme belongs to the family of ligases, specifically those forming carbon-nitrogen bonds carbon-nitrogen ligases with glutamine as amido-N-donor. The systematic name of this enzyme class is deamido-NAD+:L-glutamine amido-ligase (AMP-forming). Other names in common use include NAD+ synthetase (glutamine-hydrolysing), nicotinamide adenine dinucleotide synthetase (glutamine), desamidonicotinamide adenine dinucleotide amidotransferase, and DPN synthetase. This enzyme participates in glutamate metabolism and nicotinate and nicotinamide metabolism.