Cotranslational Assembly of Oligomeric Proteins

The assembly of newly synthesized proteins into functionally active oligomers has long been regarded as a posttranslational process driven by random collision of subunits. However, growing evidence indicates that, for many proteins, assembly occurs cotranslationally, tightly coupling synthesis, folding, and subunit assembly. This fundamentally different mechanism enables the spatial and temporal coordination of assembly, promotes the hierarchical formation of multisubunit assemblies, enhances the stability of involved subunits, enlarges the space of feasible protein structures including complexes with intertwined subunits, and has profound effects on protein evolution and function. In this review, we describe the molecular mechanisms, cellular requirements, and functional implications of cotranslational assembly and discuss its relevance to human disease, its evolutionary significance, and its transformative potential in synthetic biology and recombinant protein production.