Jin Hong, Loria J Patrick, Moore Peter B
Department of Chemistry, Yale University, New Haven, CT 06520, USA.
Mol Cell. 2007 Apr 27;26(2):205-15. doi: 10.1016/j.molcel.2007.03.014.
Base pairing between the RNA components of box H/ACA small nucleolar ribonucleoproteins (snoRNPs) and sequences in other eukaryotic RNAs target specific uridines for pseudouridylation. An RNA called HJ1 has been developed that interacts with the rRNA sequence targeted by the 5' pseudouridylation pocket of human U65 snoRNA the same way as intact U65 snoRNA. Sequences on both strands of the analog of the U65 snoRNP pseudouridylation pocket in HJ1 pair with its substrate sequence, and the resulting complex, called HJ3, is strongly stabilized by Mg(2+). The solution structure of HJ3 reveals an Omega-shaped RNA interaction motif that has not previously been described, which is likely to be common to all box H/ACA snoRNP-substrate complexes. The topology of the complex explains why the access of substrate sequences to snoRNPs is facile and how uridine selection may occur when these complexes form.
盒H/ACA小核仁核糖核蛋白（snoRNP）的RNA组分与其他真核RNA中的序列之间的碱基配对将特定尿苷靶向假尿苷化。一种名为HJ1的RNA已被开发出来，它与人类U65 snoRNA的5'假尿苷化口袋靶向的rRNA序列相互作用，方式与完整的U65 snoRNA相同。HJ1中U65 snoRNP假尿苷化口袋类似物两条链上的序列与其底物序列配对，由此产生的复合物称为HJ3，它被Mg(2+)强烈稳定。HJ3的溶液结构揭示了一种以前未被描述过的Ω形RNA相互作用基序，它可能是所有盒H/ACA snoRNP-底物复合物共有的。该复合物的拓扑结构解释了底物序列与snoRNP的结合为何容易，以及这些复合物形成时尿苷选择是如何发生的。
