This domain is found at the C-terminal end of Aminoglycoside adenylyltransferase from Salmonella typhimurium (AadA) and other proteins associated with methicillin-resistant bacteria. AadA adenylates the 3''-hydroxyl group of the streptomycin glucosamine ring and the 9-hydroxyl group of the spectinomycin actinamine ring, mediating bacterial resistance to these antibiotics. This enzyme is organised into two domains: a N-terminal domain with a nucleotidyltransferase fold (pfam01909) and a C-terminal domain (this entry) which consists of five alpha-helices forming an up-and-down alpha-helical bundle. This domain undergoes small conformational changes upon binding of ATP and magnesium that play a key role in the binding of the antibiotic compounds.
Jiyao W et al.(2023). "The conserved domain database in 2023.",