Structure of IMP3 RRM12 domain. (A) Schematic diagram showing conserved domain arrangement of IMP-family members. (B) Sequence alignment of RRM12 domains of IMP1-3. Identical residues (white), highly conserved (red), and not conserved (black) are depicted. Residues involved in the RRM1-RRM2 interface (star) and the linker-RRM2 (C terminus) interactions (triangle) are shown. (C) Domain orientation of IMP3 RRM12. RRM1 (blue), RRM2 (green), and linker (purple) with secondary structures labeled. The β-sheet surface of RRM1 is exposed to solvent, while the β-sheet surface of RRM2 is occluded by RRM1. (D) The hydrogen bonds formed in the interface of RRM1 and RRM2. (E) Hydrogen bonds and salt bridges formed between residues of linker and RRM2 (C terminus).
