DGCR8 recognizes primary transcripts of microRNAs through highly cooperative binding and formation of higher-order structures

The C-terminal helix of DGCR8 is required for trimerization of DGCR8 upon association with pri-mir-30a. (A) The values of K, Hill coefficient, and pri-mir-30a processing activity of the C-terminal truncation constructs. (B) Filter binding results of DGCR8^276–700 are shown as an example. The panel on the left is the binding data fit with a cooperative dimer model. Hill plot of the data in the binding transition is indicated on the right. (C) The residues in the α^729–749 helix are plotted on an helical wheel. The conserved residues are drawn in bold. Sequence alignment of DGCR8 homologs in this helical region is shown on the right. (D) Reconstituted pri-mir-30a processing assays. The NC1 mutants are present at 50 nM concentration. The reactions were incubated for 45 min at 37°C. (E) Summary of the pri-mir-30a binding results.