Long D M, Uhlenbeck O C
Department of Chemistry and Biochemistry, University of Colorado, Boulder 80309-0215.
FASEB J. 1993 Jan;7(1):25-30. doi: 10.1096/fasebj.7.1.8422971.
We describe the structures and catalytic properties of several naturally occurring self-cleaving RNA motifs that give 2', 3' cyclic phosphate products. The hammerhead and hairpin motifs are derived from plant pathogenic RNAs and the delta motif is part of the human hepatitis delta element. A fourth motif from Neurospora is less well characterized. By assembling the self-cleaving RNAs from more than one oligoribonucleotide, the cleavage reaction can be examined under a variety of conditions and catalytic turnover can be demonstrated. Mutagenesis and chemical methods to introduce modified nucleotides allowed the structural requirements to be deduced. The role of divalent cations in the catalytic mechanism is discussed.
我们描述了几种天然存在的自我切割RNA基序的结构和催化特性，这些基序可产生2'，3'环磷酸产物。锤头状和发夹状基序源自植物致病RNA，而δ基序是人类丁型肝炎病毒元件的一部分。来自粗糙脉孢菌的第四个基序的特征尚不明确。通过将来自多个寡核糖核苷酸的自我切割RNA组装起来，可以在各种条件下检查切割反应，并证明催化周转。通过诱变和化学方法引入修饰的核苷酸，可以推断出结构要求。讨论了二价阳离子在催化机制中的作用。
