Amidase
In enzymology, an amidase (, "acylamidase", "acylase (misleading)", "amidohydrolase (ambiguous)", "deaminase (ambiguous)", "fatty acylamidase", "N-acetylaminohydrolase (ambiguous)") is an enzyme that catalyzes the hydrolysis of an amide: Thus, the two substrates of this enzyme are an amide and HO, whereas its two products are monocarboxylate and NH. This enzyme belongs to the family of hydrolases, those acting on carbon-nitrogen bonds other than peptide bonds, specifically in linear amides. The systematic name of this enzyme class is acylamide amidohydrolase. Other names in common use include acylamidase, acylase, amidohydrolase, deaminase, fatty acylamidase, and N-acetylaminohydrolase. This enzyme participates in 6 metabolic  pathways: urea cycle and metabolism of amino groups, phenylalanine metabolism, tryptophan metabolism, cyanoamino acid metabolism, benzoate degradation via coa ligation, and styrene degradation. Amidases contain a conserved stretch of approximately 130 amino acids known as the AS sequence. They are widespread, being found in both prokaryotes and eukaryotes. AS enzymes catalyse the hydrolysis of amide bonds (CO-NH2), although the family has diverged widely with regard to substrate specificity and function. Nonetheless, these enzymes maintain a core alpha/beta/alpha structure, where the topologies of the N- and C-terminal halves are similar. AS enzymes characteristically have a highly conserved  C-terminal region rich in serine and glycine residues, but devoid of aspartic acid and histidine residues, therefore they differ from classical serine hydrolases. These enzymes possess a unique, highly conserved Ser-Ser-Lys catalytic triad used for amide hydrolysis, although the catalytic mechanism for acyl-enzyme intermediate formation can differ between enzymes. Examples of AS signature-containing enzymes include: Structural studies. As of late 2018, 162 structures have been solved for this family, which can be accessed at the Pfam.