Maize chlorotic mottle virus (MCMV) is an icosahedral plant virus 30 nm in diameter, composed of a single 25-kDa capsid protein subunit and a 4.4-kb single-stranded, positive-sense genomic RNA. The genomic RNA is capped at the 5'terminus with m 7 GpppA, and no genome-linked protein was detected. MCMV infection produces two discrete double-stranded RNA species in infected maize plants, corresponding to single-stranded RNAs of 4.4 and 1.1 kb (...)