Time course of large ribosomal subunit assembly in E. coli cells overexpressing a helicase inactive DbpA protein
Time course of large ribosomal subunit assembly in E. coli cells overexpressing a helicase inactive DbpA protein
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DOI：
10.1261/rna.055137.115
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发表时间：
2016-07-01
期刊：
影响因子：
4.5
通讯作者：
Koculi, Eda
中科院分区：
文献类型：
--
作者：
Gentry, Riley C.;Childs, Jared J.;Koculi, Eda
DbpA是大肠杆菌核糖体大亚基组装中涉及的DEAD盒RNA解旋酶。先前的研究表明，当ATP酶和解旋酶失活的DbpA构建体R331A在E.大肠杆菌细胞中，一个大的核糖体亚基中间积累。大亚基中间体作为45S颗粒在蔗糖梯度中迁移。在这里，使用一些结构和荧光检测，我们调查的核糖体配置文件的细胞缺乏野生型DbpA和过表达的R331A DbpA构建。我们的数据表明，除了先前描述的45S颗粒，27S和35S颗粒也存在于过表达R331A DbpA的细胞的核糖体谱中。27S、35S和45S独立地转化为50S亚基，表明在R331A存在和野生型DbpA不存在的情况下，核糖体组装通过多种途径发生。
DbpA is a DEAD-box RNA helicase implicated in Escherichia coli large ribosomal subunit assembly. Previous studies have shown that when the ATPase and helicase inactive DbpA construct, R331A, is expressed in E. coli cells, a large ribosomal subunit intermediate accumulates. The large subunit intermediate migrates as a 45S particle in a sucrose gradient. Here, using a number of structural and fluorescent assays, we investigate the ribosome profiles of cells lacking wild-type DbpA and overexpressing the R331A DbpA construct. Our data show that in addition to the 45S particle previously described, 27S and 35S particles are also present in the ribosome profiles of cells overexpressing R331A DbpA. The 27S, 35S, and 45S independently convert to the 50S subunit, suggesting that ribosome assembly in the presence of R331A and the absence of wild-type DbpA occurs via multiple pathways.