Objective  Two new protein phosphatase genes, MiSTPP1 and MiSTPP4, from macadamia (Macadamia integrifolia) were cloned for structure and function analyses by bioinformatics.

  Method  The genes were cloned from M. integrifolia using transcriptome sequencing and RT-PCR technique. Homology, phylogenetic evolution, physicochemical properties, phosphorylation sites, subcellular localization, transmembrane domains, and signal peptides of the genes were analyzed.

  Result  The cloned MiSTPP1 and MiSTPP4 from M. integrifolia were assigned with the GenBank accession numbers MT374548 and MT374551, respectively. The amino acid sequences of the genes had a similarity to other plant PP1 proteins containing the same typical structural domain MPP_PP1_PPKL. The evolutionary tree analysis showed that they closely related to PP1 family proteins. The basic physicochemical properties of MiSTPP1 indicated it be an unstable hydrophilic protein, and those of MiSTPP4 a stable hydrophilic protein. Phosphorylation sites on the genes were principally serine and threonine. The predicted subcellular localization, transmembrane domain, and signal peptide suggested that MiSTPP1 and MiSTPP4, as non-secretory and non-transmembrane proteins, were most likely located in the cytoplasm. The secondary and tertiary structures of the genes contained mainly α-helixes and random coils.

  Conclusion  MiSTPP1 and MiSTPP4 from macadamia belonged to the protein phosphatase PP1 gene family and might play a role in response to stress and signal transduction as well as other physiological and biochemical processes of the plant.