antibiotic acylases cephalosporin acylase and penicillin G acylase (EC 3.5.1.11) catalyze the deacylation of beta-lactam antibiotics, while aculeacin A acylase (EC 3.5.1.70) is known to be an alternative acylase class catalyzing the deacylation of echinocandin or cyclic lipopeptide antibiotic compounds
cephalosporin C acylase is the key enzyme catalyst for the hydrolysis of cephalosporin C (CPC), which directly produces the important cephalosporin antibiotic 7-aminocephalosporanic acid (7-ACA). 7-ACA is an important cephalosporin nucleus for the synthesis of many widely used beta-lactam antibiotics
the enzyme is a member of the N-terminal nucleophile (Ntn) hydrolase superfamily, in which the precursor gene is translated into a single polypeptide chain and then folded into a self-activating pre-protein activated by intramolecular double cleavages
a deep cavity constitutes the active site, structure overview. The nucleophilic catalytic serine residue, Ser1beta, is situated at the base of the active site cavity, ligand covalently binds to the catalytic serine residue forming a tetrahedral adduct and mimickingc the transition state of the enzyme for both the maturation step and the catalysis of the substrates
the protein structure of Pseudomonas SE83 CCA is obtained through the computational modeling with X-ray crystal structure of Pseudomonas N176 CCA (PDB accession code 4HST) as the template, three-dimensional structure, homology modeling, overview. The key residue of the enzyme, 1Ser of beta-subunit, is located in the active-site cavity, which is on the opposite side to the C-terminal of beta-subunit
based on structural information, a catalytic mechanism of the class III enzyme from Pseudomonas sp. strain N176 is proposed: like other N-terminal hydrolases, the N-terminal amine group acts as a base to deprotonate the hydroxyl group of the same residue. Subsequently, the N-terminal Ser1beta performs a nucleophilic attack to the carbonyl group of the substrate, resulting in the formation of a tetrahedral intermediate, which is stabilized by the oxyanion hole formed by the side chain of Asn242beta and the backbone amino group of His70beta. The reaction proceeds to cephalosporin C hydrolysis via the release of 7-aminocephalosporanic acid and the subsequent nucleophilic attack of a water molecule. Cephalosporin C (CPC) substrate binding structure and kinetics, simulation of the enzyme-substrate complex, detailed overview. The barrier results from the binding of a CPC molecule to three gatekeeper residues (S369beta, S460beta, E86alpha) at the entrance to the binding pocket, modeling using the enzyme's crystal structure, PDB ID 4HSR
cephalosporin acylase structure, PDB ID 1or0, is used to construct a three-dimensional homology model of aculeacin A acylase (EC 3.5.1.70), and docking simulation with substrate ligands. Cephalosporin acylase mutant has the deep narrow binding pocket for the long-chain fatty acyl group of the echinocandin molecule. Docking study, overview