Cristodero Marina, Böttcher Bettina, Diepholz Meikel, Scheffzek Klaus, Clayton Christine
Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany.
Mol Biochem Parasitol. 2008 May;159(1):24-9. doi: 10.1016/j.molbiopara.2007.12.012. Epub 2008 Jan 4.
The eukaryotic exosome is a complex of at least 11 proteins that is required for various 3'-5' exoribonucleolytic RNA processing and degradation reactions. The minimal core consists of 6 RNase PH and 3 S1 domain subunits; various additional proteins may be associated. We describe here the purification of native exosome from Leishmania tarentolae. The yield is sufficient for structural studies of the native exosome. Electron microscopy and image reconstruction of negatively stained preparations revealed the expected six-membered ring structure at 35 A resolution. An additional density suggested that RRP6 and its partner EAP3 (equivalent to Rrp47) might be located at the top of the exosome and at the side of the hexameric ring. No exonuclease or polyadenylation activity was detected in the exosome preparations.
真核外切体是一种由至少11种蛋白质组成的复合物，参与各种3'-5'外切核糖核酸酶RNA加工和降解反应。其最小核心由6个RNase PH和3个S1结构域亚基组成；可能还会有各种其他蛋白质与之相关联。我们在此描述了从热带利什曼原虫中纯化天然外切体的方法。该产量足以用于天然外切体的结构研究。电子显微镜和负染制剂的图像重建显示，在35埃分辨率下呈现出预期的六元环结构。另外的密度表明RRP6及其伴侣EAP3（等同于Rrp47）可能位于外切体顶部和六聚体环的侧面。在外切体制剂中未检测到核酸外切酶或聚腺苷酸化活性。
