M20 Peptidase aminoacylase 1-like protein 2-like, amidohydrolase subfamily
Peptidase M20 family, aminoacylase 1-like protein 2 (ACY1L2; amidohydrolase)-like subfamily. This group contains many uncharacterized proteins predicted as amidohydrolases, including gene products of abgA and abgB that catalyze the cleavage of p-aminobenzoyl-glutamate, a folate catabolite in Escherichia coli, to p-aminobenzoate and glutamate. p-Aminobenzoyl-glutamate utilization is catalyzed by the abg region gene product, AbgT. This subfamily includes Staphylococcus aureus antibiotic resistance factor HmrA that has been shown to participate in methicillin resistance mechanisms in vivo in the presence of beta-lactams. Aminoacylase 1 (ACY1) proteins are a class of zinc binding homodimeric enzymes involved in hydrolysis of N-acetylated proteins. N-terminal acetylation of proteins is a widespread and highly conserved process that is involved in the protection and stability of proteins. Several types of aminoacylases can be distinguished on the basis of substrate specificity. ACY1 breaks down cytosolic aliphatic N-acyl-alpha-amino acids (except L-aspartate), especially N-acetyl-methionine and acetyl-glutamate into L-amino acids and an acyl group. However, ACY1 can also catalyze the reverse reaction, the synthesis of acetylated amino acids. ACY1 may also play a role in xenobiotic bioactivation as well as the inter-organ processing of amino acid-conjugated xenobiotic derivatives (S-substituted-N-acetyl-L-cysteine).