Sensitivity of ribosomes of the hyperthermophilic bacterium Aquifex pyrophilus to aminoglycoside antibiotics

A poly(U)-programmed cell-free system from the hyperthermophilic bacterium Aquifex pyrophilus has been developed, and the susceptibility of Aquifex ribosomes to the miscoding-inducing and inhibitory actions of all known classes of aminoglycoside antibiotics has been assayed at temperatures (75 to 80 degrees C) close to the physiological optimum for cell growth. Unlike Thermotoga maritima ribosomes, which are systematically refractory to all known classes of aminoglycoside compounds (P. Londei, S. Altamura, R. Huber, K. O. Stetter, and P. Cammarano, J. Bacteriol, 170:4353-4360, 1988), Aquifex ribosomes are susceptible to all of the aminoglycosides tested (disubstituted 2-deoxystreptamines monosubstituted 2-deoxystreptamines, and streptidine compounds). The significance of this result in light of the Aquifex and Thermotoga placements in phylogenetic trees of molecular sequences is discussed.