In vivo and in vitro synthesis of the proteins expressed by the RNA of black beetle virus.

Black beetle virus is a small RNA virus with a single capsid protein of molecular weight congruent to 40,000. Two intracellular proteins, a presumed polymerase (molecular weight 110,000) and a protein having a molecular weight slightly greater than the capsid, were observed when infected Drosophila cells were pulsed with 35S-methionine. Viral RNA coded for the synthesis of several major proteins with molecular weights between 110,000 and 38,000 in rabbit reticulocyte lysate. Long chases of the translated products demonstrated processing of capsid protein precursors into capsid protein. Partial proteolysis demonstrated similarities in the proteins synthesised in vitro and in vivo.