Figure 7. A model of Gib2 interaction with the ribosome.

The Gib2 structure was superimposed onto Asc1 in the presence of S. cerevisiae ribosome (PDB: 3U5B and 3U5C)³¹ using Coot⁵⁶. (A) The model positions Gib2 to the “back” of small subunit head. The 40S subunit is shown from the side opposite from the mRNA tunnel exit with the 60S interacting interface pointing to the right. Landmarks of the 40S subunit are indicated to aid orientation. Gib2 is shown both as a cartoon and as a surface with same colouring schemes as in Figure 4. The ribosome is shown as a surface rendition with rRNA and r-proteins in grey and purple, respectively. (B) A close-up view of the Gib2 ribosome interface. Conserved and positively charged residues of Gib2 predicted to interact with the ribosome are labelled and shown as orange spheres. The ribosome is shown as a cartoon representation with the same colouring as in panel A, and regions involved in Gib2 binding are labelled. (C) Top view of Gib2 indicating the location of residues predicted to be involved in ribosome binding. β-propeller blades are numbered.