Abstract
The 3' half of the RNA of the cucurbit potyvirus zucchini yellow mosaic virus (ZYMV) was genetically cloned and the cDNA sequence of a portion of the putative RNA polymerase gene, the complete coat protein gene and the 3' untranslated region was determined. The coat protein and putative polymerase genes are both part of a continuous open reading frame as is the case for other potyviruses whose genomes are expressed as polyproteins. The Q/S protease cleavage site for the N terminus of the coat protein was deduced by alignment of the coat protein and polymerase genes with other potyviral sequences. The resulting protein has 279 amino acids and a calculated Mr of 31,214. The predicted amino acid sequence indicates a ZYMV-unique N-terminal region and potyvirus- characteristic central and C-terminal regions. These data also verify that ZYMV is distinct from the cucurbit potyvirus watermelon mosaic virus 2.