In enzymology, N-acetylglucosamine-6-phosphate deacetylase (), also known as GlcNAc-6-phosphate deacetylase or NagA, is an enzyme that catalyzes the deacetylation of N-acetylglucosamine-6-phosphate (GlcNAc-6-P) to glucosamine-6-phosphate (GlcN-6-P): H2O + N-acetyl-D-glucosamine 6-phosphate acetate + D-glucosamine 6-phosphate GlcNAc-6-phosphate deacetylase is encoded by the gene NagA. This enzyme belongs to the amidohydrolase superfamily. Amidohydrolases are a type of hydrolase that acts upon amide bonds. All members of the amidohydrolase family employ a TIM barrel structure, and a vast majority of members are metalloenzymes. The family of enzymes is important in amino acid and nucleotide metabolism as well as biodegradation of agricultural and industrial compounds. NagA participates in amino-sugar metabolism, specifically in the biosynthesis of amino-sugar-nucleotides. Structure NagA is a homodimeric enzyme with two domains in each dimer of the structure. Each domain I comprises a (β/α)8 - barrel structural fold, also known as a TIM barrel, and contains an active site of the enzyme. Each active site consists of the catalytic site of the enzyme and the metal-binding site that are involved in substrate and metal co-factor recognition, respectively. Domain I also forms the dimeric interface with domain I of the neighboring subunit. The smaller second domain of NagA enzymes comprises a β-barrel, which potentially acts to stabilize the enzyme. While all members of the amidohydrolase superfamily employ a TIM-barrel structural fold, NagA in Escherichia coli (EcNagA) has a pseudo-TIM barrel enclosing the funnel-like catalytic site of the enzyme. The dimer structure of NagA is considered crucial for the activity and thermostability of the enzyme. Metal-binding site Amidohydrolase enzymes can bind one, two, or three metal atoms in the active site. These metals can include Zn2+, Co2+, Fe2+, Cd2+, and others. EcNagA contains a mononuclear metal-binding site with a Zn2+ ion; in addition, EcNagA shows a phosphate ion bound at the metal-binding site. Unlike EcNagA, NagA of Mycobacterium smegmatis (MSNagA) and Bacillus subtilis (BsNagA) have binuclear metal-binding sites. MSNagA has two divalent metal ions located in each active site, which are both required for efficient catalysis and structural stability. While most other bacteria species use Zn as their metal co-factor, BsNagA utilizes iron as the predominant metal in the metal-binding site. Catalytic-binding site Most of the active site residues of EcNagA and BsNagA are conserved and share similar structural positions. A notable difference between mycobacterial NagA enzymes and NagA enzymes from other bacterial species is the presence of a cysteine at position 131. Other bacterial