Molecular-cloning and sequence-analysis of a segment from Andean potato mottle virus-B RNA encoding the putative RNA-polymerase.

Andean potato mottle virus (APMV), an endemic South American comovirus, has a bipartite genome consisting of two plus-strand RNA molecules (M and B RNA). We have cloned the 3 ' half of the B RNA and identified the complete sequence of the putative APMV RNA poly-merase. The RNA polymerase gene is part of a large polyprotein-encoding open reading frame. The putative, mature RNA polymerase, as deduced by comparison with the related cowpea mosaic virus (CPMV), type member of the comovirus group, is 703 amino acids long and shows a large degree of similarity with CPMV and other RNA polymerases. Andean potato mottle virus (APMV), an endemic South American comovirus, represents an important pathogen of several Solanaceae including potato, tomato an