PAROMOMYCIN AND DIHYDROSTREPTOMYCIN BINDING TO ESCHERICHIA-COLI RIBOSOMES
PAROMOMYCIN AND DIHYDROSTREPTOMYCIN BINDING TO ESCHERICHIA-COLI RIBOSOMES
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DOI：
10.1111/j.1432-1033.1976.tb10587.x
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发表时间：
1976-01-01
期刊：
影响因子：
--
通讯作者：
RAYNAUD, JP
中科院分区：
文献类型：
--
作者：
LANDO, D;COUSIN, MA;RAYNAUD, JP
Paromomycin binds specifically to a single type of binding site on the 70S streptomycin-sensitive E. coli ribosome. This site is different from that of dihydrostreptomycin since paromomycin binds to streptomycin-resistant ribosomes and since dihydrostreptomycin does not compete for paromomycin binding. Paromomycin binding, unlike dihydrostreptomycin binding, is independent of changes in ribosome concentration but influenced by Mg2+ concentration. Paromomycin does not bind to the 30S subunit of the streptomycin-sensitive ribosome, except in the presence of dihydrostreptomycin, which probably induces the conformational changes necessary for a paromomycin binding site. This induction does not occur with streptomycin-resistant ribosomes. Neither antibiotic binds to the 50S subunit. In general, binding of the 1 antibiotic increases the number of sites available for binding of the other. Both antibiotics exhibit marked non-specific binding at high antibiotic/ribosome ratios. Competition studies enabled the classification of other aminoglycosides according to their ability to compete for the paromomycin and dihydrostreptomycin binding sites. Derivatives structurally related to paromomycin compete for its binding, the degree of competition being related to antibacterial activity, but do not compete for dihydrostreptomycin binding; they increase the number of dihydrostreptomycin binding sites. Neither gentamicin nor kanamycin derivatives, which induce a high level of misreading, nor kasugamycin and spectinomycin, which do not induce misreading, compete for paromomycin or dihydrostreptomycin binding sites. Other sites may be involved in the binding of these aminoglycosides and in inducing misreading.
