Space-fill drawing of the 70S ribosome with two tRNAs (gold) and the Shine-Delgarno sequence of mRNA (red), which binds to 30S small-subunit RNA during initiation of the translation process. That binding takes place inside the ribosome, which is therefore shown in pale shades of blue and green. Drawn by David Goodsell from PDB files 2qnh and 1vsp.