Structure-function correlation of disease-related functional RNA

拱顶颗粒与多药耐药有关。我们发现，拱顶的RNA成分(拱顶RNA)与抗癌药物米托蒽醌结合。在核磁共振化学位移微扰的基础上，我们发现vault RNA与其他几种抗癌药物结合。还鉴定了药物的结合部位。通过阻断与其互补的寡核苷酸的结合部位，通过跳库捕获药物。RNA可能被抑制，从而导致多药耐药的克服。我们的合作者、京都大学的森井教授开发了由含有REV反应元件的RNA和REV多肽组成的适体。我们分析了该适配子与其配体的络合物的结构。观察到Rev多肽和配体分别与RNA形成新的氢键。推测了RNA的二级结构。适配子的结构鉴定正在进行中。据报道，由4‘-硫代脱氧核糖组成的DNA，4’-硫代DNA显示出显著的特征。特别是4‘-硫代DNA不被DNA酶I切割。我们用核磁共振确定了4’-硫代DNA的结构。DNA通常呈B型。然而，4‘-硫代DNA呈现A-形式，这是RNA的形式。DNase I通过B型狭长且相对较深的小凹槽与DNA结合。4‘-硫代DNA的小槽较浅而宽，这是A型的特征，不适合与DNA酶I结合。根据所确定的结构，还解释了4’-硫代DNA的其他显著特征。

Vault particle is related to multi-drug resistance. We found that RNA component of the vault (vault RNA)binds to anti-cancer drug, mitoxantrone. On the basis of chemical shift perturbation with NMR, we found that vault RNA binds to several other anti-cancer drugs. The binding site for drugs was also identified. By blocking the binding site with its complementary oligonucleotide, the trap of drugs by vault. RNA may be suppressed, which could lead to the overcome of the multi-drug resistance.The aptamer composed of RNA containing the Rev-responsive element and the Rev peptide was developed by our collaborator, Professor Morii of Kyoto University. We analyzed the structure of this aptamer in complex with its ligand. The formation of new hydrogen bonds was observed for RNA upon the binding of the Rev peptide and the ligand, respectively. The secondary structure of RNA was deduced. The structure determination of the aptamer is in progress.It was reported that DNA composed of the 4'-thiodeoxyriboses, 4'-thioDNA, exhibits remarkable features. Particularly, 4'-thioDNA is resistant to cleavage by DNase I. We determined the structure of 4'-thioDNA by NMR. DNA usually takes on B-form. 4'-thioDNA, however, takes on A-form which is the form for RNA. DNase I binds to DNA through the interaction at the narrow and relatively deep minor groove of the B-form. The minor groove of 4'-thioDNA is wide and shallow, which is characteristic to A-form, and is not suitable for the binding of DNase I. The other remarkable features of 4'-thioDNA were also interpreted on the basis of the determined structure.