Nucleotide Sequence of the Capsid Protein Gene of Plum Pox Potyvirus

Abstract

Summary The sequence of 1232 nucleotides from the 3′ region of the plum pox virus (PPV) RNA has been determined. This sequence contains one long open reading frame (ORF). The sequence of the 17 amino-terminal amino acids of the PPV capsid protein was determined chemically. An identical amino acid sequence was found in the translation product of the large ORF, starting at amino acid -330, which is alanine. Our data suggest that the PPV capsid protein, like that of other potyviruses, is a product of the maturation of a large polyprotein. The putative cleavage site is at a glutamine-alanine dipeptide. The capsid protein gene consists of 990 nucleotides and corresponds to a region coding for 330 amino acids which have a combined calculated M r of 36593. The adjacent 3′ untranslated region is of 215 nucleotides and ends in a polyadenylate tract. PPV capsid protein molecules are thus larger than those of the other potyviruses that have been characterized. The amino acid sequence of PPV coat protein is 47 to 60% homologous to other potyvirus coat proteins and most of the variations are in the amino-terminal region.