FIGURE 1.

(A) Hypothetical model of PTP in plants, based on F-ATPase dimer formation, as proposed by Bernardi (2013b), Bonora et al. (2013), and Alavian et al. (2014). Plant F-ATPase subunits are organized on the basis of their putative correspondence to the mammalian ones. (B) Circular phylogenetic tree of peptide sequences of homologous subunit g of mitochondrial ATP synthase in four representative taxa (i.e., Bos taurus, Drosophila melanogaster, Saccharomyces cerevisiae, and Arabidopsis thaliana). Alignments of multiple amino acid sequences were performed using MUSCLE software (Edgar, 2004). Phylogenetic trees were obtained using phyML version 3.0 with the maximum-likelihood (ML) method (Guindon et al., 2010). The NCBI Reference Sequence accession codes for the g subunit are: B. taurus = NP_001019721; D. melanogaster = NP_609142; S. cerevisiae = NP_015345; A. thaliana = NP_179558. Where more isoforms were found in NCBI databases, we randomly selected only one of these sequences.