Structure determination of archaea-specific ribosomal protein L46a reveals a novel protein fold
Structure determination of archaea-specific ribosomal protein L46a reveals a novel protein fold
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古细菌特异性核糖体蛋白 L46a 的结构测定揭示了一种新的蛋白质折叠。
DOI：
10.1016/j.bbrc.2014.05.077
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发表时间：
2014-07-18
影响因子：
3.1
通讯作者：
Wang，Jinfeng
中科院分区：
文献类型：
--
作者：
Feng，Yingang;Song，Xiaxia;Wang，Jinfeng
最近发现的三种古细菌特异性核糖体蛋白与其他已知蛋白没有序列同源性。本文利用核磁共振波谱技术对硫磺硫化叶菌P2的三种蛋白质中最保守的L46 a进行了结构测定。该结构呈现由N-末端部分和C-末端的两个螺旋形成的扭曲β-折叠。L46 a结构具有带正电荷的表面，其在L46 a蛋白家族中是保守的，并且是潜在的rRNA结合位点。在蛋白质数据库中搜索同源结构，发现L46 a的结构代表了一种新的蛋白质折叠。通过NMR弛豫实验确定的骨架动力学揭示了rRNA结合表面的显著灵活性。L46 a在核糖体上的潜在位置是通过将其结构拟合到先前的核糖体50 S亚基的电子显微镜图中提出的，该图表明L46 a与多功能核糖体蛋白L7 ae附近的23 S rRNA的结构域I接触。
Three archaea-specific ribosomal proteins recently identified show no sequence homology with other known proteins. Here we determined the structure of L46a, the most conserved one among the three proteins, fromSulfolobus solfataricusP2 using NMR spectroscopy. The structure presents a twisted β-sheet formed by the N-terminal part and two helices at the C-terminus. The L46a structure has a positively charged surface which is conserved in the L46a protein family and is the potential rRNA-binding site. Searching homologous structures in Protein Data Bank revealed that the structure of L46a represents a novel protein fold. The backbone dynamics identified by NMR relaxation experiments reveal significant flexibility at the rRNA binding surface. The potential position of L46a on the ribosome was proposed by fitting the structure into a previous electron microscopy map of the ribosomal 50S subunit, which indicated that L46a contacts to domain I of 23S rRNA near a multifunctional ribosomal protein L7ae.