The domain of the Bacillus subtilis DEAD-box helicase YxiN that is responsible for specific binding of 23S rRNA has an RNA recognition motif fold.
The domain of the Bacillus subtilis DEAD-box helicase YxiN that is responsible for specific binding of 23S rRNA has an RNA recognition motif fold.
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DOI：
10.1261/rna.5906
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发表时间：
2006-06
期刊：
影响因子：
4.5
通讯作者：
Shuying Wang;Yaoxiong Hu;M. Overgaard;Fedor V. Karginov;O. Uhlenbeck;D. Mckay
中科院分区：
文献类型：
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作者：
Shuying Wang;Yaoxiong Hu;M. Overgaard;Fedor V. Karginov;O. Uhlenbeck;D. Mckay
枯草芽孢杆菌的YxiN蛋白是原核DEAD盒RNA解旋酶的DbpA亚家族的成员。与DbpA一样，它以高亲和力和特异性结合短至32个核苷酸（nt）的23 S核糖体RNA片段，包括发夹92。几个实验已经表明，YxiN的76个残基的羧基末端结构域负责高亲和力RNA结合。该畴已结晶，其结构已解决了1.7埃的分辨率。该结构揭示了在许多真核RNA结合蛋白中发现的RNA识别基序（RRM）折叠; RRM折叠从氨基酸序列中不明显。该结构域在对应于核糖核蛋白（RNP）基序RNP1和RNP2的芳族残基的位点处具有两个溶剂暴露的芳族残基，所述基序RNP1和RNP2是许多RRM中RNA结合所必需的。然而，这些残基（Tyr404和Tyr447）突变为丙氨酸对RNA亲和力几乎没有影响，表明YxiN结构域以不同于在许多真核RRM中常见的结合模式的方式结合靶RNA。
The YxiN protein of Bacillus subtilis is a member of the DbpA subfamily of prokaryotic DEAD-box RNA helicases. Like DbpA, it binds with high affinity and specificity to segments of 23S ribosomal RNA as short as 32 nucleotides (nt) that include hairpin 92. Several experiments have shown that the 76-residue carboxy-terminal domain of YxiN is responsible for the high-affinity RNA binding. The domain has been crystallized and its structure has been solved to 1.7 Angstroms resolution. The structure reveals an RNA recognition motif (RRM) fold that is found in many eukaryotic RNA binding proteins; the RRM fold was not apparent from the amino acid sequence. The domain has two solvent exposed aromatic residues at sites that correspond to the aromatic residues of the ribonucleoprotein (RNP) motifs RNP1 and RNP2 that are essential for RNA binding in many RRMs. However, mutagenesis of these residues (Tyr404 and Tyr447) to alanine has little effect on RNA affinity, suggesting that the YxiN domain binds target RNAs in a manner that differs from the binding mode commonly found in many eukaryotic RRMs.