The UTP-A complex from <i>Chaetomium thermophilum</i>.

<p><b>(A)</b> Scheme showing the spatial assembly of the fungal UTP-A complex including the Utp4 X-ray structure and the EM-modeled 5'-ETS. The propellers of remaining UTP-A proteins (Utp8, Utp15, and 2× Utp17) are placed according previous biochemical and EM-studies. The α-solenoidal parts (including whole Utp5) are not included. The entire Utp10 molecule turning around Utp4 is interpreted as also the very C-terminus (atomic model) of Utp8 next to the Velcro-closure of Utp4. The position of the disease-modified arginine in human Utp4 in the interface to Utp10 is highlighted within a red sphere. <b>(B)</b> Comparison of the UTP-A complexes from <i>Chaetomium thermophilum</i> (left panel; [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0178752#pone.0178752.ref009" target="_blank">9</a>]) and <i>Saccharomyces cerevisiae</i> (right panel; [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0178752#pone.0178752.ref027" target="_blank">27</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0178752#pone.0178752.ref028" target="_blank">28</a>]). While the overall architecture is conserved, the 5'-end of the RNA shows a different arrangement. In addition, the Upt8-Utp4 contact is not visible in the yeast structures.