Fig. 1

Evolution of the twin arginine translocase (TAT) in eukaryotes. a Distribution of mitochondrial Tat components across eukaryotes depicts at least 21 independent losses of the signature TatC component. Previously identified TatA and TatC proteins were collected from sequenced mitochondrial genomes. Their evolutionary distribution was mapped across a consensus tree of eukaryotes. Black rectangles indicate a gene’s presence or absence in a particular mitochondrial genome. The black triangle in ochrophytes indicates that TatA has been lost on numerous occasions in this lineage. The grey rectangle depicts the lineages, where putative nucleus-encoded TatB was found. b Representation of CLANS analysis of 1111 TatB protein sequences demonstrating separation of bacterial and mitochondrial TatB sequences (P value threshold of 10⁻¹⁰). Bacterial sequences are shown as black dots and mitochondrial proteins of plants and ochrophytes as green and red dots, respectively. c Schematic tree showing that mitochondrial TatC is monophyletic. Predicted protein sequences of TatC from eukaryotes and a subset of prokaryotes, focusing on alphaproteobacteria, were aligned using MUSCLE and subjected to phylogenetic reconstructions using MrBayes for computing posterior probability and RaxML for maximum likelihood (see the ‘Materials and methods’ section for more detail and Additional file 1: Figure S1 for complete tree). Support values are as inset (MrBayes/RaxML)