Structural insights into translational recoding by frameshift suppressor tRNA^SufJ

Modeling tRNA^SufJ interactions in the A and P sites. (A) Modeling studies extending our structure of ASL^SufJ (blue) to a full-length tRNA^SufJ (white outlined with blue) reveal that the tilting position of the stem region would result in the CCA end of tRNA^SufJ >20 Å distant from the position of an accommodated A-site tRNA (gold) (arrow at the CCA end indicates the difference). We predict that conformational rearrangements of tRNA^SufJ are required to prevent this interaction with the ribosome. (B) The P-site tRNA^fMet (purple) is gripped by 16S rRNA G1338 and A1339 (gray) by the formation of A-minor interactions with both C40-G30 and C41-G29 (PDB code 2J02). (C) Superposition of ASL^SufJ on the anticodon of tRNA^fMet in the P site suggests that the deformation of the stem domain would prevent the formation of canonical G1338 and A1339 interactions. A semitransparent overlay of the superpositioning of ASL^Thr is shown for comparison (light gray).