Slipknotted and unknotted monovalent cation-proton antiporters evolved from a common ancestor
Fig 6
Seven evolutionary scenarios found within the transporters.
1) No fusion—diversification of the ancestor gene leading to one-domain protein. 2) Long diversification—gene duplication followed by an extended period of diversification which lead to two domains with low sequence similarity (shown with red and blue). 3) Duplication of already fused protein (PF13593 speciated from PF01758, PF06965 from PF00999). 4) Reverse-order fusion—gene duplication and fusion in a reverse order. 5) Fusion of the domains from different lineages (shown with blue and green). 6) Fast fusion—gene duplication followed by an instant fusion (in families PF05145, PF06826 and PF03956). 7) Fusion of unrelated lineages (PF05982).