KINETIC-PROPERTIES OF ESCHERICHIA-COLI RIBOSOMES WITH ALTERED FORMS OF S12
KINETIC-PROPERTIES OF ESCHERICHIA-COLI RIBOSOMES WITH ALTERED FORMS OF S12
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DOI：
10.1016/0022-2836(92)90466-w
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发表时间：
1992-04-20
影响因子：
5.6
通讯作者：
EHRENBERG, M
中科院分区：
文献类型：
--
作者：
BILGIN, N;CLAESENS, F;EHRENBERG, M
E.本文用猝灭流技术研究了引起链霉素耐药（SmR）、依赖性（SmD）和假依赖性（SmP）的S_（12）改变的大肠杆菌核糖体。确定了在伸长周期的各个步骤的动力学变化。与野生型核糖体相比，在SmD和SmP中，核糖体A位点的三元复合物中GTP的水解速率急剧下降。添加链霉素可以恢复大部分野生型行为。SmD、SmP和SmR核糖体在EF-Tu上具有增强的GTP水解空转反应，这与这些核糖体在稳态测定中的积极性有关。我们利用我们的体外研究结果来讨论这些突变体的体内生理学以及E.大肠杆菌转化
E. coliribosomes with alterations in S12 leading to streptomycin resistance (SmR), dependence (SmD) and pseudodependence (SmP) were studied with the quench-flow technique. Kinetic changes at the various steps of the elongation cycle were identified. The rate of hydrolysis of GTP in the ternary complex in the ribosomal A-site is decreased drastically in SmD and moderately in SmP in relation to wild-type ribosomes. Addition of streptomycin restores much of the wild-type behaviour. The SmD, SmP and SmR ribosomes have an enhanced GTP-hydrolysis idling reaction on EF-Tu, which is correlated with how aggressive proofreaders these ribosomes are in steady-state assays. We use ourin vitrofindings to discuss thein vivophysiology of these mutants as well as mechanistic features ofE. colitranslation.