Preservation of 5'-end integrity of a potyvirus genomic RNA is not dependent on template specificity

Abstract Full-length in vitro transcripts of plum pox potyvirus (PPV) genomic RNA with mutations altering the number of 5′-terminal adenosine residues were able to infect Nicotiana clevelandii plants, whereas a mutant with a substitution of adenosine in position 2 by guanosine failed to infect. The genomic 5′ end was template-independently repaired during in vivo RNA synthesis producing wild-type viral progeny. Putative models of replication initiation are discussed.