Crystal Structure of the N-Terminal RNA Recognition Motif of mRNA Decay Regulator AUF1

Figure 2

Overall structure of AUF1-. (a) Stereo diagram of P2₁2₁2₁ symmetry packings of AUF1-. The highlighted red box represents the dimeric RRM1 molecules in the asymmetric unit. (b) Overall structure of dimeric AUF1-. The two RRM1 molecules are colored in yellow and cyan. The 90° rotated view along the -axis is shown in the lower panel. (c) Overlay of the two RRM1 molecules. Conformational differences of the L1 (β2-β3) and L2 (α2-β4) loops are indicated by red and blue arrows, respectively. (d) Overlay of the two RRM1 molecules with the RRM1 (pink) and RRM2 (gray) molecules from the NMR structures. The L1 and L2 loops are indicated as shown in (c). (e) Overlay of RRM1-Mol. 2 (cyan) with hnRNP A1-RRM1 (green; PDB entry 2UP1), HuR-RRM1 apo (blue; PDB entry 4EGL), and HuR-RRM1-RNA (gray; PDB entries 4ED5). The L1 and L2 loops are indicated as shown in (c). (f) B-factor presentations of the RRM1 from two monomers of AUF1, HuR, and hnRNP A1, as indicated below. The B-factor represents the dynamic mobility of the different resolved parts within the structure. The thicker lines with warmer colors indicate higher mobility. Each of the L1 loops is represented by red arrows.

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