Department of Life and Environmental Sciences, Polytechnic University of Marche, Via Brecce Bianche, 60131 Ancona, Italy.
New York-Marche Structural Biology Center (Ny-MaSBiC), Polytechnic University of Marche, Via Brecce Bianche, 60131 Ancona, Italy.
Biomolecules. 2022 Oct 6;12(10):1432. doi: 10.3390/biom12101432.
The translation factor IF5A is a highly conserved protein playing a well-recognized and well-characterized role in protein synthesis; nevertheless, some of its features as well as its abundance in the cell suggest that it may perform additional functions related to RNA metabolism. Here, we have undertaken a structural and functional characterization of aIF5A from the crenarchaeal model organism. We confirm the association of aIF5A with several RNA molecules in vivo and demonstrate that the protein is endowed with a ribonuclease activity which is specific for long and structured RNA. By means of biochemical and structural approaches we show that aIF5A can exist in both monomeric and dimeric conformations and the monomer formation is favored by the association with RNA. Finally, modelling of the three-dimensional structure of aIF5A shows an extended positively charged surface which may explain its strong tendency to associate to RNA in vivo.
翻译因子 IF5A 是一种高度保守的蛋白质，在蛋白质合成中发挥着公认的、特征明确的作用；然而，其某些特性及其在细胞中的丰度表明，它可能具有与 RNA 代谢相关的其他功能。在这里，我们对来自古菌模式生物的 aIF5A 进行了结构和功能表征。我们证实了 aIF5A 与体内几种 RNA 分子的关联，并证明该蛋白具有核酶活性，专门作用于长而结构化的 RNA。通过生化和结构方法，我们表明 aIF5A 可以存在于单体和二聚体构象中，并且单体形成受与 RNA 的结合促进。最后，aIF5A 的三维结构建模显示出一个扩展的带正电荷的表面，这可以解释其在体内与 RNA 强烈结合的趋势。
