Fig. 3

Mitochondrial TatC of Naegleria gruberi. a Protein sequence alignment of bacterial and mitochondrial TatC proteins. The blue rectangle highlights the conserved glutamate/glutamine residue in the center of TatC cavity. The yellow rectangle depicts the position of conserved phenylalanine and glutamate residue of the signal peptide binding site. The green rectangle highlights the insertion common to heterolobosean TatC, and grey cylinders depict the transmembrane domains. Identical and similar residues are highlighted in pink and grey colour, respectively. The threshold for shading was 50%. The C-terminal peptide used for antibody generation is underlined. b The comparison of structure of bacterial TatC protein from A. aeolicus [17] and TatC from A. godoyi and N. gruberi obtained by I-TASSER [69]. N. gruberi protein shows overall relaxed structure with unclear arrangement of the fifth membrane spanning domain c Western blot analyses of N. gruberi cellular fractions. d NgTatC forms high molecular weight complexes on BN-PAGE in mitochondria (Ng) and also when expressed with C-terminal HA-tag in E. coli (Ec). In both cases, the membranes were solubilised in 2% digitonin