A minor outer capsid protein, P9, of Rice dwarf virus

Partial amino acid sequence of a minor 30 kDa polypeptide in purified Rice dwarf virus (RDV) was identical to the deduced amino acid sequence encoded by the dsRNA segment S9 of the virus. This polypeptide was specifically detected by Western blotting analysis with antibodies raised against the product of S9 expressed in a baculovirus system. Treatment of purified RDV particles with a relatively higher concentration of MgCl2 removed the polypeptide from core particles together with other outer capsid proteins. These results demonstrate that the 30 kDa polypeptide is a minor outer capsid protein that is encoded by genome segment S9 of RDV. This protein was named P9 protein.