Aminoglycoside 3-N-acetyltransferase type IIa (AAC(3)-IIa)

Aminoglycoside 3-N-acetyltransferase type IIa (AAC(3)-IIa) is a bacterial enzyme belonging to the aminoglycoside acetyltransferase family, specifically the GNAT superfamily. It mediates resistance to several clinically important aminoglycoside antibiotics (including gentamicin, kanamycin, tobramycin, neomycin, and apramycin) by catalyzing the transfer of an acetyl group from acetyl-CoA to the N3 amine of the 2-deoxystreptamine ring present in these drugs. This enzymatic modification renders the antibiotics unable to bind to their bacterial ribosomal targets, thus conferring resistance. AAC(3)-IIa is frequently detected in Gram-negative pathogens and is of major clinical significance due to its role in antibiotic resistance, which can complicate the treatment of severe bacterial infections.

Other names

AAC(3)-IIaAminoglycoside N(3)-acetyltransferase IIaaacC2 (gene name)aminoglycoside-resistance acetyltransferase IIa

Enzymatic acetylation (N-acetylation) of aminoglycoside antibiotics at the N3 position of the 2-deoxystreptamine ring, which results in drug inactivation and bacterial resistance.