A 5-proximal Stem-loop Structure of 5 Untranslated Region of Porcine Reproductive and Respiratory Syndrome Virus Genome Is Key for Virus Replication

摘要

BackgroundIt has been well documented that the 5' untranslated region (5' UTR) of many positive-stranded RNA viruses contain key cis-acting regulatory sequences, as well as high-order structural elements. Little is known for such regulatory elements controlling porcine arterivirus replication. We investigated the roles of a conserved stem-loop 2 (SL2) that resides in the 5'UTR of the genome of a type II porcine reproductive and respiratory syndrome virus (PRRSV).