Ssh10b, a conserved thermophilic archaeal protein, binds RNA in vivo
Ssh10b, a conserved thermophilic archaeal protein, binds RNA in vivo
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DOI：
10.1046/j.1365-2958.2003.03793.x
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发表时间：
2003-12-01
影响因子：
3.6
通讯作者：
Huang, L
中科院分区：
文献类型：
--
作者：
Guo, R;Xue, H;Huang, L
Sac 10 b家族的蛋白质在超嗜热古菌中高度保守，被认为是DNA结合蛋白。基于它们的体外DNA结合特性，这些蛋白质被认为参与染色体组织或DNA修复/重组。我们表明，Ssh 10 b，Sac 10 b家族的成员从柴田硫化叶菌，结合类似的亲和力，双链DNA，单链DNA和RNA在体外。然而，在S. Shibatae细胞，如通过体内UV交联和免疫共沉淀所揭示的。核糖体RNA是与Ssh 10 b共免疫沉淀的RNA种类之一。与该观察结果一致，Ssh 10 b在低盐条件下与核糖体共纯化。此外，我们通过紫外线交联杂交证明，当细胞用紫外线照射时，Ssh 10 b与16 S，23 S rRNA和mRNA交联。我们的数据表明，RNA是Sac 10 b家族的生理结合靶标。
Proteins of the Sac10b family, which is highly conserved among hyperthermophilic archaea, have been regarded as DNA-binding proteins. Based on their in vitro DNA-binding properties, these proteins are thought to be involved in chromosomal organization or DNA repair/recombination. We show that Ssh10b, a member of the Sac10b family from Sulfolobus shibatae, bound with similar affinities to double-stranded DNA, single-stranded DNA and RNA in vitro. However, the protein was exclusively bound to RNA in S. shibatae cells, as revealed by in vivo UV cross-linking and co-immunoprecipitation. Ribosomal RNAs were among the RNA species co-immunoprecipitated with Ssh10b. Consistent with this observation, Ssh10b was co-purified with ribosomes under low salt conditions. Furthermore, we demonstrate by UV-cross-linking hybridization that, when the cells were irradiated with UV, Ssh10b became cross-linked to 16S, 23S rRNAs and mRNAs. Our data indicate that RNA is the physiological binding target of the Sac10b family.