Figure 3. Interactions between RelA and the ribosome.
a, Overview (left) and details (right) of the interaction between the ZFD (orange) and RRM (blue) of RelA and the ribosomal ASF (light blue) that spans the intersubunit interface between the P-site (green) and A-site (purple) tRNAs. RelA acts as an additional intersubunit bridge by binding uL16 (cyan) in the large subunit and uS19 (yellow) in the small subunit. b, The α-helix of the ZFD binds in the major groove of the ASF, with the zinc-binding site interacting with the phosphate backbone. c, By binding to uS19, the ZFD occupies the position adopted by the ASF in the rotated ribosome (grey).