MUSHROOM BACILLIFORM VIRUS-RNA - THE INITIATION OF TRANSLATION AT THE5' END OF THE GENOME AND IDENTIFICATION OF THE VPG

Mushroom bacilliform Virus (MBV) is often found in cultivated mushroom s (Agaricus bisporus) with La France disease. MBV has a 4-kb ssRNA gen ome of positive-sense encoding four major open reading frames (ORFs). The arrangement of ORFs at the 5' end of the genome and the deduced am ino-acid sequences of two of the putative gene products (protease and RNA-dependent RNA polymerase) show remarkable similarity to some plant viruses, particularly subgroup II luteoviruses. We show that this sim ilarity extends to the translation strategy at the 5' end of the genom e, the presence of a genome-linked protein (VPg), and the location of the VPg downstream of the protease motifs in the polypeptide encoded b y ORF2. (C) 1998 Academic Press.