FIG. 6.

Views of the RRM1 residues important for nuclear export that are masked or functionally overridden by the NRE in the isolated RRM1 (A) and in the LM-RRM1-UUU-OH RNA complex (B). (A) The mutated RRM1 residues that restored nuclear accumulation to the NRE-defective hLa proteins are shown in green; the mutated residues that restored nuclear accumulation and suppression (E132, D133, and F150) are shown as side chains. Mutated residues that did not restore nuclear accumulation are shown in blue, including Y114 and F155, the highly conserved aromatic side chains on the β-sheet surface. (B) The LM is shown in gold. The 3′ UUU-OH (U7 U8 U9 [37]) is shown in red, with the rest of the RNA chain in blue.