Discovery of potential phytases of the purple acid phosphatase family in a wide range of photosynthetic organisms and insights into their structure and evolution

PAPhys are phytases that belong to the family of purple acid phosphatases (PAPs). Currently, there is limited information about how to distinguish a PAPhy sequence from a PAP without phytase activity. PAPhys have only been identified in angiosperm plants; therefore, it is unknown how prevalent they are in other photosynthetic organisms and what their phylogenetic relationships are. Therefore, the purpose of this research is to discover potential PAPhys using novel PAPhy-associated motifs and provide new information on their phylogeny. Experimentally validated PAPhys were identified and analyzed using the neighbor-joining phylogeny, and from each clade, a consensus sequence (CS) was generated. CSs were analyzed with the Multiple Em for Motif Elicitation (MEME) tool to identify characteristic motifs; with these motifs, potential PAPhys were searched in a broad range of photosynthetic organisms using the Motif Alignment & Search Tool (MAST). Genes encoding potential PAPhys were analyzed by maximum-likelihood phylogeny. Twenty-one PAPhys were identified in the literature and resolved into five clades. The MEME analysis generated four PAPhy-associated motifs (M1 to M4). A total of 160 potential PAPhys were identified with MAST. The phylogeny of these potential PAPhys revealed 11 major clades, among which six clades do not possess any experimentally studied PAPhy. The PAPhy motifs identified in this work were useful for identifying potential PAPhys. Phylogenetic analysis suggested that PAPhys are an ancient class of proteins in photosynthetic organisms. These new insights have provided valuable information on the evolution of this class of phytases and may assist in the cloning of novel PAPhys, which could lead to biotechnological applications.