The central role of protein S12 in organizing the structure of the decoding site of the ribosome.
The central role of protein S12 in organizing the structure of the decoding site of the ribosome.
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DOI：
10.1261/rna.040030.113
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发表时间：
2013-12
期刊：
影响因子：
--
通讯作者：
Gregory ST
中科院分区：
文献类型：
--
作者：
Demirci H;Wang L;Murphy FV 4th;Murphy EL;Carr JF;Blanchard SC;Jogl G;Dahlberg AE;Gregory ST
核糖体的结构研究为解码中心同源密码子-反密码子相互作用如何导致tRNA选择并最终导致肽链延伸提供了深刻的见解。在遗传和结构上易于处理的嗜热热菌（Thermus thermophilus）中，作者分离并鉴定了链霉素依赖（SmD）核糖体变异，以及链霉素独立（SmI）复合体，突变分别影响核糖体蛋白S12和16S rRNA。单分子FRET和结构研究揭示了这些解码位点近端突变如何影响核糖体达到tRNA选择进展所需的gtpase激活状态的能力。核糖体通过在构象动态解码位点内使用一组普遍保守的16S rRNA核苷酸监测密码子-反密码子碱基配对的几何形状来解码mRNA。通过应用单分子FRET和x射线晶体学，我们已经确定核糖体蛋白S12的条件致死性链霉素依赖性突变通过允许解码位点的构象扭曲来干扰tRNA选择，从而在tRNA选择过程中损害EF-Tu的GTPase激活。解码位点的扭曲被链霉素或16S rRNA的第二位点抑制突变逆转。这些观察结果鼓励对当前解码模型的改进，其中核糖体蛋白S12和解码位点在tRNA选择过程的早期阶段合作优化密码子识别和底物区分。
Structural studies on the ribosome have provided tremendous insights into how cognate codon–anticodon interactions in the decoding center lead to tRNA selection and, ultimately, to peptide chain elongation. Here, in the genetically and structurally tractable organism Thermus thermophilus, the authors isolate and identify streptomycin-dependent (SmD) ribosomal variants, as well as streptomycin-independent (SmI) revertants, with mutations affecting ribosomal protein S12 and the 16S rRNA, respectively. Single-molecule FRET and structural studies reveal here how these decoding-site proximal mutations can impact the ability of ribosomes to reach the GTPase-activated state required for progression in tRNA selection. The ribosome decodes mRNA by monitoring the geometry of codon–anticodon base-pairing using a set of universally conserved 16S rRNA nucleotides within the conformationally dynamic decoding site. By applying single-molecule FRET and X-ray crystallography, we have determined that conditional-lethal, streptomycin-dependence mutations in ribosomal protein S12 interfere with tRNA selection by allowing conformational distortions of the decoding site that impair GTPase activation of EF-Tu during the tRNA selection process. Distortions in the decoding site are reversed by streptomycin or by a second-site suppressor mutation in 16S rRNA. These observations encourage a refinement of the current model for decoding, wherein ribosomal protein S12 and the decoding site collaborate to optimize codon recognition and substrate discrimination during the early stages of the tRNA selection process.
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影响因子：
5.6
作者：
BILGIN, N;CLAESENS, F;EHRENBERG, M
通讯作者：
EHRENBERG, M
DOI：
10.1107/s0907444909052925
发表时间：
2010-02
期刊：
Acta crystallographica. Section D, Biological crystallography
影响因子：
--
作者：
Adams PD;Afonine PV;Bunkóczi G;Chen VB;Davis IW;Echols N;Headd JJ;Hung LW;Kapral GJ;Grosse-Kunstleve RW;McCoy AJ;Moriarty NW;Oeffner R;Read RJ;Richardson DC;Richardson JS;Terwilliger TC;Zwart PH
通讯作者：
Zwart PH
影响因子：
56.9
作者：
Carter, AP;Clemons, WM;Ramakrishnan, V
通讯作者：
Ramakrishnan, V
影响因子：
3.2
作者：
Carr, JF;Gregory, ST;Dahlberg, AE
通讯作者：
Dahlberg, AE
影响因子：
64.5
作者：
ALLEN, PN;NOLLER, HF
通讯作者：
NOLLER, HF