Fig. 3.

PRE experiments reveal the structure of the Dcp2 enzyme in solution. (A) The correlation of PREs measured on the Dcp1:Dcp2 complex and PREs that are back-calculated based on the Dcp2 protein in orientation 1a confirm that the apo Dcp1:Dcp2 complex adopts this orientation in solution (see also SI Appendix, Fig. S3). Residues located in the Dcp2 RD are indicated in yellow and residues in the CD in green. The spin label at Dcp1-S49C is indicated in the structure with a yellow sphere; the measured PREs are displayed as red to blue spheres. (B) Same as in A, but for the Dcp1:Dcp2:Edc1 complex that adopts orientation 1a in solution (see also SI Appendix, Fig. S5). (C) Same as in A, but for Dcp1:Dcp2:Edc1:substrate complex that adopts orientation 6 in solution (see also SI Appendix, Fig. S7). (D) Path of the RNA on the structure of the Dcp1:Dcp2:Edc1:m7GDP complex (orientation 6b). The complex is colored according to the electrostatic surface potential. The nucleotides toward the 3′ end of the substrate interact with the box B region in the Dcp2 CD (see also SI Appendix, Fig. S11).