?
Aminoglycoside 3'-phosphotransferase APH catalyzes the transfer of the gamma-phosphoryl group from ATP to aminoglycoside antibiotics such as kanamycin, streptomycin, neomycin, and gentamicin, among others. The aminoglycoside antibiotics target the 30S ribosome and promote miscoding, leading to the production of defective proteins which insert into the bacterial membrane, resulting in membrane damage and the ultimate demise of the bacterium. Phosphorylation of the aminoglycoside antibiotics results in their inactivation, leading to bacterial antibiotic resistance. The APH gene is found on transposons and plasmids and is thought to have originated as a self-defense mechanism used by microorganisms that produce the antibiotics. The APH subfamily is part of a larger superfamily that includes the catalytic domains of other kinases, such as the typical serine/threonine/tyrosine protein kinases (PKs), RIO kinases, actin-fragmin kinase (AFK), and phosphoinositide 3-kinase (PI3K).
|