Fig. 1

Domain sequence alignment of predicted TPC proteins. a Schematic illustration of TPC proteins, illustrating the 12 transmembrane domains (IS1–6 and IIS1–6), the pore regions (P1 and 2), the filter regions (F1 and 2) and the EF hands (EF1 and 2) [22]. TPC2 protein sequences from Dictyostelium discoideum (DdTPC2) aligned with Arabidopsis TPC1 (AtTPC1), rice TPC1 (OsTPC1) and human TPCs (HsTPC1 and HsTPC2) are shown. b The first six transmembrane domains and EF hands and c the second six transmembrane domains. The prediction of secondary structure is based on the published structure of AtTPC1 [22] [23]; except IIS0 which is predicted based on [24]. Stars illustrate potential voltage-sensing residues [23]. The sequences were aligned using ClustalW built-in BioEdit