Blaha Gregor, Stanley Robin E, Steitz Thomas A
Department of Molecular Biophysics, Yale University, New Haven, CT 06520, USA.
Science. 2009 Aug 21;325(5943):966-70. doi: 10.1126/science.1175800.
Elongation factor P (EF-P) is an essential protein that stimulates the formation of the first peptide bond in protein synthesis. Here we report the crystal structure of EF-P bound to the Thermus thermophilus 70S ribosome along with the initiator transfer RNA N-formyl-methionyl-tRNA(i) (fMet-tRNA(i)(fMet)) and a short piece of messenger RNA (mRNA) at a resolution of 3.5 angstroms. EF-P binds to a site located between the binding site for the peptidyl tRNA (P site) and the exiting tRNA (E site). It spans both ribosomal subunits with its amino-terminal domain positioned adjacent to the aminoacyl acceptor stem and its carboxyl-terminal domain positioned next to the anticodon stem-loop of the P site-bound initiator tRNA. Domain II of EF-P interacts with the ribosomal protein L1, which results in the largest movement of the L1 stalk that has been observed in the absence of ratcheting of the ribosomal subunits. EF-P facilitates the proper positioning of the fMet-tRNA(i)(fMet) for the formation of the first peptide bond during translation initiation.
延伸因子P（EF-P）是一种在蛋白质合成中刺激第一个肽键形成的必需蛋白质。在此，我们报道了与嗜热栖热菌70S核糖体结合的EF-P的晶体结构，同时还有起始转运RNA N-甲酰甲硫氨酰-tRNA(i)（fMet-tRNA(i)(fMet)）和一小段信使RNA（mRNA），分辨率为3.5埃。EF-P结合在肽基tRNA（P位点）结合位点和退出的tRNA（E位点）之间的一个位点上。它跨越两个核糖体亚基，其氨基末端结构域位于氨酰受体茎附近，其羧基末端结构域位于P位点结合的起始tRNA的反密码子茎环旁边。EF-P的结构域II与核糖体蛋白L1相互作用，这导致在核糖体亚基没有棘轮运动的情况下观察到的L1柄的最大移动。EF-P有助于在翻译起始过程中fMet-tRNA(i)(fMet)正确定位以形成第一个肽键。
