STRUCTURE OF THE DSRNA BINDING DOMAIN OF ESCHERICHIA-COLI RNASE-III
STRUCTURE OF THE DSRNA BINDING DOMAIN OF ESCHERICHIA-COLI RNASE-III
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DOI：
10.1002/j.1460-2075.1995.tb07363.x
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发表时间：
1995-07-17
期刊：
影响因子：
11.4
通讯作者：
PASTORE, A
中科院分区：
文献类型：
--
作者：
KHARRAT, A;MACIAS, MJ;PASTORE, A
双链RNA结合域（dsRBD）是一种类似于70个残基基的结构，存在于多种具有不同功能的模块化蛋白中，但总是与dsRNA相关。我们在这里报告了RNase III的dsRBD的结构，RNase III是一种存在于大多数，也许是所有活细胞中的酶。它通过短发夹序列的切割参与转录本的加工，如rRNA前体。RNase III蛋白由两个模块组成，一个类似于150个残基n端催化结构域，一个类似于70个残基c端识别模块，与其他dsrbd同源。利用同核磁共振技术研究了大肠杆菌中表达的dsRBD的结构，并利用一种新的计算策略进行了求解。它被发现具有- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -拓扑结构，其中三股反平行- - -片在一侧与两个螺旋相对。对44个对齐的dsRBD序列的检查显示了几个保守的带正电的残基。这些残基映射到第二螺旋的n端和附近的环，从而形成了结构域和dsRNA之间可能接触的模型。
The double-stranded RNA binding domain (dsRBD) is a similar to 70 residue motif found in a variety of modular proteins exhibiting diverse functions, yet always in assocation with dsRNA. We report here the structure of the dsRBD from RNase III, an enzyme present in most, perhaps all, living cells. It is involved in processing transcripts, such as rRNA precursors, by cleavage at short hairpin sequences. The RNase III protein consists of two modules, a similar to 150 residue N-terminal catalytic domain and a similar to 70 residue C-terminal recognition module, homologous with other dsRBDs. The structure of the dsRBD expressed in Escherichia coli has been investigated by homonuclear NMR techniques and solved with the aid of a novel calculation strategy. It was found to have an alpha-beta-beta-beta-alpha topology in which a three-stranded anti-parallel beta-sheet packs on one side against the two helices. Examination of 44 aligned dsRBD sequences reveals several conserved, positively charged residues. These residues map to the N-terminus of the second helix and a nearby loop, leading to a model for the possible contacts between the domain and dsRNA.