Joachimiak A, Basavappa R, Barciszewska M Z, Nalaskowska M, Barciszewski J
Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznań.
Acta Biochim Pol. 1990;37(3):359-75.
A new model of secondary and tertiary structure of higher plant 5S rRNA is proposed. It consists of three domains. Domain alpha includes stem I and loop A; domain beta contains stems II and III and loops B and C; domain gamma consists of stems IV and V and loops D and E. We propose that the domains beta and gamma adopt RNA-A like structure due to irregularities caused by the different in size internal loops B and E and the bulges occurring in the model. A suggested bending of RNA could bring single stranded fragments of domains beta and gamma close enough to each other to allow tertiary interactions. The new model of plant 5S rRNA differs from those suggested previously for eukaryotic 5S rRNA, by arrangement of the domains beta and gamma and the base pairing scheme of domain gamma. The model is based on our results of partial digestion obtained with single and double strand specific nucleases. The experimental results were confirmed by computer aided secondary structure prediction analysis of all higher plant 5S rRNAs and computer modeling using energy minimalization approach. Further support of our model have been provided by experiments including alpha sarcin, ribonuclease H and chemical modifications.
提出了一种高等植物5S rRNA二级和三级结构的新模型。它由三个结构域组成。α结构域包括茎I和环A；β结构域包含茎II和III以及环B和C；γ结构域由茎IV和V以及环D和E组成。我们提出，由于模型中内部环B和E大小不同以及凸起导致的不规则性，β和γ结构域采用类似RNA - A的结构。RNA的一种推测弯曲可能会使β和γ结构域的单链片段彼此足够靠近，从而允许三级相互作用。植物5S rRNA的新模型在β和γ结构域的排列以及γ结构域的碱基配对方案方面与先前针对真核生物5S rRNA提出的模型不同。该模型基于我们用单链和双链特异性核酸酶进行部分消化的结果。通过对所有高等植物5S rRNAs的计算机辅助二级结构预测分析以及使用能量最小化方法的计算机建模，证实了实验结果。包括α - 肌动蛋白、核糖核酸酶H和化学修饰在内的实验为我们的模型提供了进一步支持。
