MAPPING OF THE RED-CLOVER NECROTIC MOSAIC-VIRUS SUBGENOMIC RNA

The red clover necrotic mosaic dianthovirus capsid protein is expresse d in vivo from a subgenomic RNA (sgRNA) identical to the 3'-terminal 1 .5 kb of RNA-1. The 5' leader sequence of the capsid protein sgRNA is 62 nucleotides, contains a 14-nucleotide putative promoter sequence ho mologous to the RNA-1 5' terminus, and exhibits a high level of simila rity with the tobacco mosaic virus 5' leader translational enhancer el ement Omega. Analysis of the RNA-1 secondary structure, in the region adjacent to the position where the 5' end of the sgRNA was mapped, pre dicts a stable stem-loop which includes the putative sgRNA promoter el ement. It is suggested that this structure is important for recognitio n of the sgRNA transcriptional initiation from the full-length negativ e-sense RNA-1. (C) 1996 Academic Press, Inc.