Figure 7.

The ago1-12 Allele Provides Evidence for a Catalytic Tetrad in Plants.

(A) Overview showing the location of the ago1-12 mutation.

(B) Close-up view of the Hs-Ago2 active site region showing the catalytic tetrad (EDDH). The ago1-12 H765L mutation disrupts the H-bond to the deeply conserved Glu (Glu-736 in Hs-Ago2), with the active site residue suggested to be recruited for slicing.

(C) The proximity of the Trp binding sites and the E736 loop (in red). Interactors bound to the Trp binding pockets could reach the E736 loop and thereby modulate its active site recruitment. Note that A865V missense mutation in ago1-40 is located in this area expected to be included in the GW interaction surface.