Nomanbhoy T, Morales A J, Abraham A T, Vörtler C S, Giegé R, Schimmel P
The Skaggs Institute for Chemical Biology, The Scripps Research Institute, Beckman Center, 10550 North Torrey Pines Road, La Jolla, California 92037, USA.
Nat Struct Biol. 2001 Apr;8(4):344-8. doi: 10.1038/86228.
Transfer RNA (tRNA) is a small nucleic acid (typically 76 nucleotides) that forms binary complexes with proteins, such as aminoacyl tRNA synthetases (RS) and Trbp111. The latter is a widely distributed structure-specific tRNA-binding protein that is incorporated into cell signaling molecules. The structure of Trbp111 was modeled onto to the outer, convex side of the L-shaped tRNA. Here we present RNA footprints that are consistent with this model. This binding mode is in contrast to that of tRNA synthetases, which bind to the inside, or concave side, of tRNA. These opposite locations of binding for these two proteins suggest the possibility of a ternary complex. The formation of a tRNA synthetase--tRNA--Trbp111 ternary complex was detected by two independent methods. The results indicate that the tRNA is sandwiched between the two protein molecules. A thermodynamic and functional analysis is consistent with the tRNA retaining its native structure in the ternary complex. These results may have implications for how the translation apparatus is linked to other cellular machinery.
转运RNA（tRNA）是一种小核酸（通常为76个核苷酸），它与蛋白质形成二元复合物，如氨酰tRNA合成酶（RS）和Trbp111。后者是一种广泛分布的结构特异性tRNA结合蛋白，可整合到细胞信号分子中。Trbp111的结构被模拟到L形tRNA的外侧凸面上。在此我们展示了与该模型一致的RNA足迹。这种结合模式与tRNA合成酶的不同，tRNA合成酶结合在tRNA的内侧或凹面上。这两种蛋白质的相反结合位置提示了形成三元复合物的可能性。通过两种独立方法检测到了tRNA合成酶 - tRNA - Trbp111三元复合物的形成。结果表明tRNA夹在两个蛋白质分子之间。热力学和功能分析表明tRNA在三元复合物中保留了其天然结构。这些结果可能对翻译装置如何与其他细胞机制相联系具有启示意义。
