(A) Sequence alignment of the known activators of decapping Edc1, Edc2, and PRNC2 with Edc1 from S. pombe that we identified here. (B) Crystal structure of the Dcp1:Edc1 complex. Important interactions between Edc1 and Dcp1 are indicated. Dcp1 is colored blue and Edc1 is colored yellow. (C) Residues in Dcp1 that sample multiple conformations in the absence of binding partners are indicated with red spheres. Note that the exchange process is restricted to the Dcp1 aromatic groove that is the binding site for Xrn1, Pat1, Dhh1, the Dcp2 C terminus, and Edc1. (D) Exemplary CPMG dispersion profiles in Dcp1 in the absence (red) and in the presence (blue) of Xrn1. The interaction between Xrn1 and Dcp1 results in a quenching of the observed motions.
