(a) Cotranslational folding, modification, and interaction with ribosome-associated chaperones. The large ribosomal subunits that interact with the ribosome-associated chaperones NAC, Ssb/RAC, and SRP (themselves not depicted) are indicated in color (L17 stands for Rpl17, L25 stands for Rpl25, and L31 stands for Rpl31; figure adapted from [15]). (b) Cotranslational assembly of cellular complexes. A newly synthesized protein (in black) associates with its partner protein (in red) already during its synthesis (figure adapted from [16]).