Mixed subunit capsids can be assembled in vitro with coat protein subunits from two cucumoviruses

Abstract

Virus particles were reassembled in vitro from tomato aspermy virus strain V (V-TAV) RNA and a mixture of subunits prepared from V-TAV and 35S-labelled cucumber mosaic virus strain T (T-CMV). Immunodiffusion tests showed that the reassembled particles reacted with polyclonal antisera raised against both V-TAV and T-CMV. Radioactivity was found in the precipitin line formed between the reassembled particles and antiserum raised against T-CMV as well as in the precipitin line formed between the reassembled particles and antiserum raised against V-TAV. This shows that 35S-labelled T-CMV protein subunits were incorporated with V-TAV protein subunits into the same particles. Thus, coat proteins of V-TAV and T-CMV can coassemble and form mixed-subunit capsids in vitro.