Ennifar E, Nikulin A, Tishchenko S, Serganov A, Nevskaya N, Garber M, Ehresmann B, Ehresmann C, Nikonov S, Dumas P
UPR 9002 du CNRS, IBMC, 15 rue R. Descartes, 67084 Strasbourg-cedex, France.
J Mol Biol. 2000 Nov 17;304(1):35-42. doi: 10.1006/jmbi.2000.4204.
All large structured RNAs contain hairpin motifs made of a stem closed by several looped nucleotides. The most frequent loop motif is the UUCG one. This motif belongs to the tetraloop family and has the peculiarity of being highly thermodynamically stable. Here, we report the first crystal structure of two UUCG tetraloops embedded in a larger RNA-protein complex solved at 2.8 A resolution. The two loops present in the asymmetric unit are in a different crystal packing environment but, nevertheless, have an identical conformation. The observed structure is globally close to that obtained in solution by nuclear magnetic resonance. However, subtle differences point to a more detailed picture of the role played by 2'-hydroxyl groups in stabilising this tetraloop.
所有大型结构化RNA都含有由茎和几个环状核苷酸组成的发夹基序。最常见的环基序是UUCG基序。该基序属于四环家族，其特点是具有高度的热力学稳定性。在此，我们报道了嵌入更大的RNA-蛋白质复合物中的两个UUCG四环的首个晶体结构，该结构以2.8埃分辨率解析。不对称单元中存在的两个环处于不同的晶体堆积环境，但仍具有相同的构象。观察到的结构总体上与通过核磁共振在溶液中获得的结构相近。然而，细微的差异表明2'-羟基在稳定该四环中所起作用的更详细情况。
