Figure 7.

Superposition of TbRRP44-NPIN, TbRRP41 and TbRRP41 models and the yeast exosome subunits counterparts ScRrp44 (NPIN domain), ScRrp41 and ScRrp42 (PDB 4IFD, channel route conformation). (a) Overall structure of the assembly. The proteins are identified with different colors. The loop formed by residues 60–68 in ScRrp44 is highlighted in dark blue. TbRRP42 C-terminal extension (dark red) collides with TbRRP44-NPIN according to the structural prediction. (b) Detail of the subunits interface. TbRRP42 C-terminal was omitted for clarity. ScRrp44 side chains involved in intermolecular hydrogen bonds and salt bridges which are not conserved in TbRRP44-NPIN are shown in sticks and labeled. Substitutions in TbRRP44 are indicated in parenthesis.