The Amino-Terminal Region of Major Capsid Protein P3 Is Essential for Self-Assembly of Single-Shelled Core-Like Particles of Rice Dwarf Virus

The core protein P3 of Rice dwarf virus constructs asymmetric dimers, one of which is inserted by the amino-terminal region of another P3 protein. The P3 proteins with serial amino-terminal deletions, expressed in a baculovirus system, formed particles with gradually decreasing stability. The capacity for self-assembly disappeared when 52 of the amino-terminal amino acids had been deleted. These results demonstrated that insertion of the amino-terminal arm of one P3 protein into another appears to play an important role in stabilizing the core particles.