Penicillin G acylase (PGA) belongs to a family of beta-lactam acylases that includes cephalosporin acylase (CA) and aculeacin A acylase. PGA and CA are crucial for the production of backbone chemicals like 6-aminopenicillanic acid and 7-aminocephalosporanic acid (7-ACA), which can be used to synthesize semi-synthetic penicillins and cephalosporins, respectively. While both PGA and CA have a conserved Ntn (N-terminal nucleophile) hydrolase fold and the structural similarity at their active sites is very high, their sequence similarity is low.
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