Cloning and characterization of the immunodominant membrane protein of mulberry yellow dwarf phytoplasma

Abstract

Mulberry yellow dwarf (MYD) disease is a quarantine disease in China and the causal agent is a phytoplasma. The antigenic membrane protein (Amp) of the ‘‘Candidatus Phytoplasma asteris’’ was hypothesized to play an important role in insect transmission specificity. Here, we firstly cloned and characterized Amp gene from the ‘‘Candidatus Phytoplasma asteris’’, MYD strain. The results showed that the MYD Amp gene consisted of 702 nt encoding a predicted protein of 233 aa which was highly similar to Amp of ‘‘Candidatus Phytoplasma asteris’’, sumac witches’-broom phytoplasma (SWB) strain and mulberry dwarf phytoplasma (MD) strain. Prediction of protein structure showed that the MYD-Amp protein possess an N-terminal export leader sequence (Amp-E), a large central hydrophilic domain (Amp-H) and a C-terminal transmembrane domain with a short hydrophilic domain (Amp-T).

Key words: Mulberry yellow dwarf phytoplasma, Immunodominant membrane protein.