Pseudouridine formation in archaeal RNAs: The case of Haloferax volcanii
Pseudouridine formation in archaeal RNAs: The case of Haloferax volcanii
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DOI：
10.1261/rna.2712811
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发表时间：
2011-07-01
期刊：
影响因子：
4.5
通讯作者：
Gupta, Ramesh
中科院分区：
文献类型：
--
作者：
Blaby, Ian K.;Majumder, Mrinmoyee;Gupta, Ramesh
假尿苷（Psi）是尿苷的异构体，常见于所有生物体的非编码RNA的不同位置。Psi残基由许多单位点或多位点特异性Psi合酶形成，它们通常充当独立的蛋白质。此外，在真核生物和真核生物中，特定的核糖核蛋白复合物，每个复合物包含一个不同的盒H/ACA引导RNA和四个核心蛋白，可以在不同细胞RNA的许多位点产生Psi。Cbf 5是这些复合物中的核心Psi合酶。使用Haloferax volcanii作为古菌模式生物，我们表明，与真核生物相反，Cbf 5同源物（HVO_2493）是不是必不可少的，在这个古菌。Cbf 5缺失的H. volcanii在其23 S rRNA的位置1940、1942、2605和2591（大肠杆菌位置1915、1917、2572和2586）处完全缺乏Psi，并且含有降低的稳态水平的一些盒H/ACA RNA。已知大肠杆菌Cbf 5在体外具有tRNA Psi 55合酶活性，但我们不能在H.火山相反，Pus 10（以前的PsuX）同源物（HVO_1979），可以在体外产生tRNA Psi 55和Psi 54，在这里被证明是H. volcanii中的Psi 55 tRNA合成酶，而Pus 4和TruB在酵母和大肠杆菌中不是必需的。大肠杆菌中表达。最后，我们证明HVO_1852（TruA/Pus 3同源物）负责H中第39位的假尿苷化。volcanii的tRNA，相应的基因不是必需的。
Pseudouridine (Psi), the isomer of uridine, is commonly found at various positions of noncoding RNAs of all organisms. Psi residues are formed by a number of single-or multisite specific Psi synthases, which generally act as stand-alone proteins. In addition, in Eukarya and Archaea, specific ribonucleoprotein complexes, each containing a distinct box H/ACA guide RNA and four core proteins, can produce Psi at many sites of different cellular RNAs. Cbf5 is the core Psi synthase in these complexes. Using Haloferax volcanii as an archaeal model organism, we show that, contrary to eukaryotes, the Cbf5 homolog (HVO_2493) is not essential in this archaeon. The Cbf5-deleted strain of H. volcanii completely lacks Psi at positions 1940, 1942, 2605, and 2591 (Escherichia coli positions 1915, 1917, 2572, and 2586) of its 23S rRNA, and contains reduced steady-state levels of some box H/ACA RNAs. Archaeal Cbf5 is known to have tRNA Psi 55 synthase activity in vitro but we could not confirm this activity in vivo in H. volcanii. Conversely, the Pus10 (previously PsuX) homolog (HVO_1979), which can produce tRNA Psi 55, as well as Psi 54 in vitro, is shown here to be essential in H. volcanii, whereas the corresponding tRNA Psi 55 synthases, Pus4 and TruB, are not essential in yeast and E. coli, respectively. Finally, we demonstrate that HVO_1852, the TruA/Pus3 homolog, is responsible for the pseudouridylation of position 39 in H. volcanii tRNAs and that the corresponding gene is not essential.