Fig. 1: SAMURI-catalyzed propargyl transfer reaction and the overall structure.
From: Structure and catalytic activity of the SAM-utilizing ribozyme SAMURI
a, SAMURI transfers the propargyl group from ProSeDMA to N3 of adenosine and releases SeDHA. The reactive adenosine A52 is located in between P1 and P3. The dotted loops are present in the final crystallization construct. b, Sequence of the 58-nt crystallized RNA (R2; Supplementary Table 1) resulting in the postcatalytic structure with proA52 and SeDHA. c, Native PAGE analysis of a streptavidin-binding assay comparing the complex in solution and in the dissolved crystals, followed by copper-catalyzed click reaction with biotin azide, confirming the propargyl modification of the crystallized RNA (representative image from two independent experiments). d, Cartoon illustration of the three-dimensional structure of SAMURI. e, Schematic secondary-structure diagram with the four-layer architecture of the catalytic core highlighted in blue, red, green and yellow. f,g, Zoomed-in view of the cofactor-binding site in top (f) and side (g) views. The blue mesh represents the σA-weighted 2Fo − Fc map contoured at 1σ, while the position of SeDHA is confirmed by the Fo − Fc omit map (green, contoured at 3σ).
