Figure 2.

Structure of K. lactis Xrn1. (a). Schematic drawing of the structure of K. lactis Xrn1. The domains are colored as in Fig. 1 and labeled. The Mn²⁺ ion in the active site is shown as a sphere in dark gray. (b). Structure of K. lactis Xrn1, viewed along the arrow indicated in panel a. (c). Overlay of the structures of K. lactis Xrn1 and S. pombe Rat1 ²⁶. For simplicity, the linker between CR1 and CR2 and domains D1–D4 of Xrn1 are not shown. All the structure figures were produced with PyMOL (www.pymol.org) unless stated otherwise.