Nevskaya Natalia, Tishchenko Svetlana, Volchkov Sergey, Kljashtorny Vladislav, Nikonova Ekaterina, Nikonov Oleg, Nikulin Alexei, Köhrer Caroline, Piendl Wolfgang, Zimmermann Robert, Stockley Peter, Garber Maria, Nikonov Stanislav
Institute of Protein Research, Russian Academy of Sciences, 142290 Pushchino, Moscow region, Russian Federation.
J Mol Biol. 2006 Jan 27;355(4):747-59. doi: 10.1016/j.jmb.2005.10.084. Epub 2005 Nov 17.
The RNA-binding ability of ribosomal protein L1 is of profound interest, since L1 has a dual function as a ribosomal structural protein that binds rRNA and as a translational repressor that binds its own mRNA. Here, we report the crystal structure at 2.6 A resolution of ribosomal protein L1 from the bacterium Thermus thermophilus in complex with a 38 nt fragment of L1 mRNA from Methanoccocus vannielii. The conformation of RNA-bound T.thermophilus L1 differs dramatically from that of the isolated protein. Analysis of four copies of the L1-mRNA complex in the crystal has shown that domain II of the protein does not contribute to mRNA-specific binding. A detailed comparison of the protein-RNA interactions in the L1-mRNA and L1-rRNA complexes identified amino acid residues of L1 crucial for recognition of its specific targets on the both RNAs. Incorporation of the structure of bacterial L1 into a model of the Escherichia coli ribosome revealed two additional contact regions for L1 on the 23S rRNA that were not identified in previous ribosome models.
核糖体蛋白L1的RNA结合能力备受关注，因为L1具有双重功能，既是结合rRNA的核糖体结构蛋白，又是结合自身mRNA的翻译抑制因子。在此，我们报道了嗜热栖热菌核糖体蛋白L1与来自万氏甲烷球菌的L1 mRNA的38 nt片段形成复合物的2.6 Å分辨率晶体结构。结合RNA的嗜热栖热菌L1的构象与分离的蛋白质有显著差异。对晶体中四个L1-mRNA复合物拷贝的分析表明，该蛋白的结构域II对mRNA特异性结合没有贡献。对L1-mRNA和L1-rRNA复合物中蛋白质-RNA相互作用的详细比较确定了L1中对识别两种RNA上特定靶标至关重要的氨基酸残基。将细菌L1的结构纳入大肠杆菌核糖体模型后，发现23S rRNA上还有两个L1的额外接触区域，这在以前的核糖体模型中未被识别。
