Binding enhancement by tertiary interactions and suicide inhibition of a Candida albicans group I intron by phosphoramidate and 2'-O-methyl hexanucleotides.
Binding enhancement by tertiary interactions and suicide inhibition of a Candida albicans group I intron by phosphoramidate and 2'-O-methyl hexanucleotides.
复制标题
通过三级相互作用增强结合，通过氨基磷酸酯和 2-O-甲基六核苷酸对白色念珠菌 I 组内含子进行自杀抑制。
DOI：
10.1021/bi002009j
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发表时间：
2001
期刊：
影响因子：
2.9
通讯作者：
Turner,DH
中科院分区：
文献类型：
--
作者：
Disney,MD;Matray,T;Gryaznov,SM;Turner,DH
白色念珠菌是对当前治疗逐渐产生耐药性的许多感染性病原体之一。RNA为对抗这些生物体的新疗法提供了一大类靶标。靶向RNA的一种策略是使用短寡核苷酸，除了沃森-克里克配对外，短寡核苷酸还通过三级相互作用表现出结合增强。白念珠菌的一个潜在的RNA靶标是LSU rRNA前体中的自我剪接I组内含子。与来自该前体的核酶的5'外显子剪接位点对齐的识别元件是复杂的[迪士尼，M. D、海达里斯角G.，Turner，D. H.（2001）Biochemistry 40，6507 - 6519]。这些识别元件已用于指导5'外显子的六核苷酸模拟物的设计，所述六核苷酸模拟物具有针对核酸酶稳定性而修饰的主链。这些hexanucleotides绑定多达100000倍更紧密地从内含子的核酶比一个hexanucleotide模拟内含子的内部指导序列，r（GGAGGC）。这些寡核苷酸中的几种通过自杀抑制机制抑制前体自剪接。最有前途的自杀抑制剂是核糖磷酰胺rn（GCCUC）rU，其在1 mM Mg 2+下在>100 nM的寡核苷酸浓度下形成比顺式剪接产物更多的反式剪接产物。结果表明，当三级相互作用的元件复杂时，为核酸酶稳定性而修饰的短寡核苷酸可以靶向催化RNA。
Candida albicansis one of many infectious pathogens that are evolving resistance to current treatments. RNAs provide a large class of targets for new therapeutics for fighting these organisms. One strategy for targeting RNAs uses short oligonucleotides that exhibit binding enhancement by tertiary interactions in addition to Watson−Crick pairing. A potential RNA target inC.albicansis the self-splicing group I intron in the LSU rRNA precursor. The recognition elements that align the 5‘ exon splice site for a ribozyme derived from this precursor are complex [Disney, M. D., Haidaris, C. G., and Turner, D. H. (2001)Biochemistry 40, 6507−6519]. These recognition elements have been used to guide design of hexanucleotide mimics of the 5‘ exon that have backbones modified for nuclease stability. These hexanucleotides bind as much as 100000-fold more tightly to a ribozyme derived from the intron than to a hexanucleotide mimic of the intron's internal guide sequence, r(GGAGGC). Several of these oligonucleotides inhibit precursor self-splicing via a suicide inhibition mechanism. The most promising suicide inhibitor is the ribophosphoramidate rn(GCCUC)rU, which forms more trans-spliced than cis-spliced product at oligonucleotide concentrations of >100 nM at 1 mM Mg2+. The results indicate that short oligonucleotides modified for nuclease stability can target catalytic RNAs when the elements of tertiary interactions are complex.