MOLECULAR-CLONING AND COMPLETE NUCLEOTIDE-SEQUENCE OF GALINSOGA MOSAIC-VIRUS GENOMIC RNA

The complete genomic sequence of galinsoga mosaic virus (GaMV) was det ermined. The genome consists of 3803 nucleotides and has five open rea ding frames (ORFs). The 5' ORF (ORF 1) encodes a protein with predicte d molecular mass of 23 kDa and readthrough of its amber stop codon pro bably yields a 82 kDa protein (ORF 2). ORFs 3 and 4 encode two polypep tides with molecular masses of 8 and 7 kDa, respectively. ORF 5 encode s the 36 kDa capsid protein. Amino acid sequence comparisons revealed that the nonstructural proteins encoded by ORFs 1, 3, and 4 were more similar to the corresponding gene products of tobacco necrosis virus, strain A, than to those of carmoviruses. Conversely, the coat protein was more similar to that of tombusviruses. The readthrough region of t he viral replicase (ORF 2) had high sequence homology with that of car mo-, tombus-, and necrovinuses. Computer analysis of the protein encod ed by ORF I as well as of the corresponding product of turnip crinkle (TCV) and melon necrotic spot (MNSV) carmoviruses revealed the presenc e of a sequence with local hydrophobicity and hydrophobic moment chara cteristic of mitochondrial targeting sequence which may explain the or igin of the carmovirus-induced multivesicular bodies from mitochondria .