Determining the interaction status and evolutionary fate of duplicated homomeric proteins
Fig 4
Different modes of prokaryotic homomer to eukaryotic heteromer transition.
Gene duplication of an ancestral non-ring-like homomer may produce a heteromeric complex that may (i) or may not (ii) retain the ancestral oligomeric order (i.e., the total number of subunits in the complex). After the first gene duplication and the subsequent emergence of a heteromeric interaction, multiple rounds of duplication may follow in which the descendant paralogs retain the heteromeric interaction (iii). For ring-like complexes, multiple rounds of intra-ring gene duplications result in heteromeric rings, while keeping (iv) or changing the ancestral oligomeric order (v). For each mode of transition, an example case is provided.