The family of box ACA small nucleolar RNAs is defined by an evolutionarily conserved secondary structure and ubiquitous sequence elements essential for RNA accumulation
The family of box ACA small nucleolar RNAs is defined by an evolutionarily conserved secondary structure and ubiquitous sequence elements essential for RNA accumulation
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DOI：
10.1101/gad.11.7.941
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发表时间：
1997-04-01
影响因子：
10.5
通讯作者：
Kiss, T
中科院分区：
文献类型：
--
作者：
Ganot, P;CaizerguesFerrer, M;Kiss, T
真核细胞含有大量的小核仁rna （small nucleolar rna, snoRNAs）。一个主要的snoRNAs家族具有共识的ACA基序，位于RNA的3'端3个核苷酸处。在这项研究中，我们鉴定了9个新的人类ACA snoRNAs （U64-U72）。对U64 RNA进行结构探测，然后对所有已知的盒状ACA snoRNAs进行系统计算机建模，结果表明该类snoRNAs由一个系统发育保守的二级结构定义。ACA snorna折叠成两个发夹结构，由单链铰链区域连接，然后是一个短的3'尾。铰链区域携带一个进化上保守的序列基序，称为box H （consensus, AnAnnA）。H盒可能与之前描述的侧翼螺旋结构和ACA盒一致，在人类U64内含子snoRNA的积累中起着至关重要的作用。酵母ACA snoRNA snR36在哺乳动物细胞中的正确加工表明，ACA snoRNA加工和积累所需的顺式和反式作用元件是进化保守的。ACA snoRNAs具有共同的二级结构和可能作为常见蛋白质（例如GAR1）结合位点的保守盒元件的概念表明，这些rna具有密切相关的核仁功能。
Eukaryotic cells contain a large number of small nucleolar RNAs (snoRNAs). A. major family of snoRNAs features a consensus ACA motif positioned 3 nucleotides from the 3' end of the RNA. In this study we have characterized nine novel human ACA snoRNAs (U64-U72). Structural probing of U64 RNA followed by systematic computer modeling of all known box ACA snoRNAs revealed that this class of snoRNAs is defined by a phylogenetically conserved secondary structure. The ACA snoRNAs fold into two hairpin structures connected by a single-stranded hinge region and followed by a short 3' tail. The hinge region carries an evolutionarily conserved sequence motif, called box H (consensus, AnAnnA). The H box, probably in concert with the flanking helix structures and the ACA box characterized previously, plays an essential role in the accumulation of human U64 intronic snoRNA. The correct processing of a yeast ACA snoRNA, snR36, in mammalian cells demonstrated that the cis- and trans-acting elements required for processing and accumulation of ACA snoRNAs are evolutionarily conserved. The notion that ACA snoRNAs share a common secondary structure and conserved box elements that likely function as binding sites for common proteins (e.g., GAR1) suggests that these RNAs possess closely related nucleolar functions.