Gaudin Cyril, Mazauric Marie-Hélène, Traïkia Mounir, Guittet Eric, Yoshizawa Satoko, Fourmy Dominique
Laboratoire de RMN, ICSN-CNRS 1 ave de la terrasse, 91190 Gif-sur-Yvette, France.
J Mol Biol. 2005 Jun 24;349(5):1024-35. doi: 10.1016/j.jmb.2005.04.045.
Many pathogenic viruses use a programmed -1 translational frameshifting mechanism to regulate synthesis of their structural and enzymatic proteins. Frameshifting is vital for viral replication. A slippery sequence bound at the ribosomal A and P sites as well as a downstream stimulatory RNA structure are essential for frameshifting. Conflicting data have been reported concerning the structure of the downstream RNA signal in human immunodeficiency virus type 1 (HIV-1). Here, the solution structure of the HIV-1 frameshifting RNA signal was solved by heteronuclear NMR spectroscopy. This structure reveals a long hairpin fold with an internal three-nucleotide bulge. The internal loop introduces a bend between the lower and upper helical regions, a structural feature often seen in frameshifting pseudoknots. The NMR structure correlates with chemical probing data. The upper stem rich in conserved G-C Watson-Crick base-pairs is highly stable, whereas the bulge region and the lower stem are more flexible.
许多致病病毒利用程序性-1翻译移码机制来调控其结构蛋白和酶蛋白的合成。移码对于病毒复制至关重要。位于核糖体A位和P位的一段滑序列以及下游的刺激RNA结构是移码所必需的。关于1型人类免疫缺陷病毒（HIV-1）下游RNA信号的结构，已有相互矛盾的数据报道。在此，通过异核核磁共振光谱法解析了HIV-1移码RNA信号的溶液结构。该结构揭示了一个带有内部三核苷酸凸起的长发夹折叠。内部环在下部和上部螺旋区域之间引入了一个弯曲，这是移码假结中常见的结构特征。核磁共振结构与化学探针数据相关。富含保守G-C沃森-克里克碱基对的上部茎高度稳定，而凸起区域和下部茎则更具柔性。
