密码子识别复合物中氨酰tRNA与延伸因子Tu的核糖体相互作用。

Ribosome interactions of aminoacyl-tRNA and elongation factor Tu in the codon-recognition complex.

作者信息

Stark Holger, Rodnina Marina V, Wieden Hans-Joachim, Zemlin Friedrich, Wintermeyer Wolfgang, van Heel Marin

机构信息

Max-Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany.

出版信息

Nat Struct Biol. 2002 Nov;9(11):849-54. doi: 10.1038/nsb859.

DOI:10.1038/nsb859

PMID:12379845

Abstract

The mRNA codon in the ribosomal A-site is recognized by aminoacyl-tRNA (aa-tRNA) in a ternary complex with elongation factor Tu (EF-Tu) and GTP. Here we report the 13 A resolution three-dimensional reconstruction determined by cryo-electron microscopy of the kirromycin-stalled codon-recognition complex. The structure of the ternary complex is distorted by binding of the tRNA anticodon arm in the decoding center. The aa-tRNA interacts with 16S rRNA, helix 69 of 23S rRNA and proteins S12 and L11, while the sarcin-ricin loop of 23S rRNA contacts domain 1 of EF-Tu near the nucleotide-binding pocket. These results provide a detailed snapshot view of an important functional state of the ribosome and suggest mechanisms of decoding and GTPase activation.

摘要

核糖体A位点中的mRNA密码子由氨酰-tRNA（aa-tRNA）识别，该氨酰-tRNA与延伸因子Tu（EF-Tu）和GTP形成三元复合物。在此，我们报告了通过冷冻电子显微镜确定的13 Å分辨率的三维重建结果，该重建针对的是奇霉素停滞的密码子识别复合物。三元复合物的结构因解码中心中tRNA反密码子臂的结合而发生扭曲。氨酰-tRNA与16S rRNA、23S rRNA的螺旋69以及蛋白质S12和L11相互作用，而23S rRNA的肌动蛋白-蓖麻毒素环在核苷酸结合口袋附近与EF-Tu的结构域1接触。这些结果提供了核糖体重要功能状态的详细快照视图，并提示了解码和GTP酶激活的机制。