Papaya mosaic potexvirus (PapMV) coat protein (CP) was expressed (CPDN5) inEscherichia coliand showed to self assemble into nucleocapsid like particles (NLPs). Twenty per cent of the purified protein was found as NLPs of 50 nm in length and 80% was found as a multimer of 450 kDa (20 subunits) arranged in a disk.