Fig. 2From: Shedding light on the expansion and diversification of the Cdc48 protein family during the rise of the eukaryotic cellEvolutionary tree of the individual AAA domains of the different Cdc48 family members. The tree was constructed from the individual AAA domains (D1- and D2-domains) of the Cdc48 family using a selection of 48 eukaryotic and 26 archaeal species, accounting for a total of 687 AAA domains. The representative species are listed in Additional file 2: Table S2. The different family members are highlighted in different colors, while D1- and D2-domains of the same protein have the same color. Statistical support values (likelihood-mapping/IQ-TREE support/RAxML support/PhyML support) are given at selected inner edges. Most AAA domains form short branches and split into a D1 and a D2 subtree, in which the two domains of all archaeal Cdc48 are located close to the center of the tree, probably reflecting the fact that the eukaryotic family members are derived from a primordial VAT [19]. However, in the tree all archaea sequences, even from the recently found Lokiarchaeota, are well-separated from eukaryotic family members. The two more divergent D1-domains of the peroxins and the D2 domain of the N-ethylmaleimide sensitive factor (NSF) form long branches. Notably, the D2-domain of NSF is located in the D1 subtree, whereas the D1-domain of NSF is found in the D2 subtree. A similar pattern had been observed in earlier studies and it has been suggested that the two domains of NSF have been swapped during evolution [118]. Given the generally conserved architecture of the protein family, this scenario is not very likely [39]. It is much more probable that this branching pattern is caused by long-branch attraction. In fact, when we included the incomplete, long-branching D2-domain of Yta7, the branching pattern of the two NSF domains changed (Additional file 11: Figure S7)Back to article page