Barbas Ana, Matos Rute G, Amblar Mónica, López-Viñas Eduardo, Gomez-Puertas Paulino, Arraiano Cecília M
Instituto de Tecnologia Química e Biológica/Universidade Nova de Lisboa, Apartado 127, 2781-901 Oeiras, Portugal.
J Biol Chem. 2008 May 9;283(19):13070-6. doi: 10.1074/jbc.M709989200. Epub 2008 Mar 12.
RNase II is a key exoribonuclease involved in the maturation, turnover, and quality control of RNA. RNase II homologues are components of the exosome, a complex of exoribonucleases. The structure of RNase II unraveled crucial aspects of the mechanism of RNA degradation. Here we show that mutations in highly conserved residues at the active site affect the activity of the enzyme. Moreover, we have identified the residue that is responsible for setting the end product of RNase II. In addition, we present for the first time the models of two members of the RNase II family, RNase R from Escherichia coli and human Rrp44, also called Dis3. Our findings improve the present model for RNA degradation by the RNase II family of enzymes.
核糖核酸酶II是一种关键的外切核糖核酸酶，参与RNA的成熟、周转和质量控制。核糖核酸酶II同源物是外切体的组成部分，外切体是一种外切核糖核酸酶复合物。核糖核酸酶II的结构揭示了RNA降解机制的关键方面。在这里，我们表明活性位点高度保守残基的突变会影响该酶的活性。此外，我们确定了负责确定核糖核酸酶II终产物的残基。此外，我们首次展示了核糖核酸酶II家族的两个成员的模型，即来自大肠杆菌的核糖核酸酶R和人类Rrp44（也称为Dis3）。我们的发现改进了目前关于核糖核酸酶II家族酶降解RNA的模型。
